Subjects -> CHEMISTRY (Total: 928 journals)
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CHEMISTRY (661 journals)            First | 1 2 3 4 | Last

Showing 401 - 600 of 735 Journals sorted alphabetically
Journal of Molecular Liquids     Hybrid Journal   (Followers: 3)
Journal of Molecular Modeling     Hybrid Journal   (Followers: 5)
Journal of Molecular Recognition     Hybrid Journal   (Followers: 2)
Journal of Molecular Spectroscopy     Hybrid Journal   (Followers: 6)
Journal of Molecular Structure     Hybrid Journal   (Followers: 6)
Journal of Nanoparticles     Open Access   (Followers: 4)
Journal of Nanostructure in Chemistry     Open Access   (Followers: 8)
Journal of Organometallic Chemistry     Hybrid Journal   (Followers: 24)
Journal of Photochemistry and Photobiology     Open Access  
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 3)
Journal of Photochemistry and Photobiology B: Biology     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 3)
Journal of Polymer & Composites     Full-text available via subscription   (Followers: 17)
Journal of Polymer and Biopolymer Physics Chemistry     Open Access   (Followers: 7)
Journal of Polymer Science Part A: Polymer Chemistry     Hybrid Journal   (Followers: 92)
Journal of Polymers     Open Access   (Followers: 7)
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 1)
Journal of Progressive Research in Chemistry     Open Access  
Journal of Pure and Applied Chemistry Research     Open Access   (Followers: 3)
Journal of Raman Spectroscopy     Hybrid Journal   (Followers: 14)
Journal of Research and Education Chemistry     Open Access   (Followers: 1)
Journal of Research Updates in Polymer Science     Hybrid Journal   (Followers: 2)
Journal of Rubber Research     Hybrid Journal   (Followers: 1)
Journal of Saudi Chemical Society     Open Access  
Journal of Solid State Chemistry     Hybrid Journal   (Followers: 13)
Journal of Solution Chemistry     Hybrid Journal   (Followers: 1)
Journal of Structural Chemistry     Hybrid Journal   (Followers: 1)
Journal of Sulfur Chemistry     Hybrid Journal   (Followers: 1)
Journal of Supercritical Fluids     Hybrid Journal   (Followers: 3)
Journal of Superhard Materials     Hybrid Journal  
Journal of Surface Science and Technology     Hybrid Journal  
Journal of Surfactants and Detergents     Hybrid Journal   (Followers: 3)
Journal of Taibah University for Science     Open Access  
Journal of the American Chemical Society     Hybrid Journal   (Followers: 326)
Journal of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 31)
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 2)
Journal of the Chilean Chemical Society     Open Access   (Followers: 2)
Journal of the Chinese Chemical Society     Hybrid Journal  
Journal of the Indian Chemical Society     Hybrid Journal  
Journal of The Indonesian Society of Integrated Chemistry     Open Access  
Journal of the Iranian Chemical Society     Hybrid Journal   (Followers: 1)
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal  
Journal of the Mexican Chemical Society     Open Access   (Followers: 1)
Journal of the Serbian Chemical Society     Open Access  
Journal of the Turkish Chemical Society, Section A : Chemistry     Open Access  
Journal of Theoretical and Computational Chemistry     Hybrid Journal   (Followers: 9)
Jurnal Inovasi Pendidikan Kimia     Open Access  
Jurnal Kimia (Journal of Chemistry)     Open Access  
Jurnal Kimia Riset     Open Access  
Jurnal Pendidikan Kimia     Open Access  
Jurnal Penelitian Sains (JPS)     Open Access  
Karbala International Journal of Modern Science     Open Access  
Kinetics and Catalysis     Hybrid Journal   (Followers: 4)
Konfigurasi : Jurnal Pendidikan Kimia dan Terapan     Open Access  
Korea-Australia Rheology Journal     Hybrid Journal   (Followers: 1)
Langmuir     Hybrid Journal   (Followers: 58)
Lebensmittelchemie     Hybrid Journal   (Followers: 1)
Lipid Insights     Open Access  
Luminescence     Hybrid Journal   (Followers: 2)
Macromolecular Materials & Engineering     Hybrid Journal   (Followers: 5)
Macromolecular Rapid Communications     Hybrid Journal   (Followers: 10)
Macromolecular Research     Hybrid Journal   (Followers: 2)
Macromolecular Symposia     Hybrid Journal   (Followers: 3)
Macromolecular Theory and Simulations     Hybrid Journal   (Followers: 2)
Macromolecules     Hybrid Journal   (Followers: 48)
Magnetic Resonance in Chemistry     Hybrid Journal   (Followers: 8)
Magnetochemistry     Open Access  
Marine Chemistry     Hybrid Journal   (Followers: 6)
Marine Drugs     Open Access   (Followers: 1)
MATEC Web of Conferences     Open Access  
Materials Advances     Open Access   (Followers: 2)
Materials and Devices     Open Access  
Materials Characterization     Hybrid Journal   (Followers: 32)
Materials Chemistry Frontiers     Hybrid Journal   (Followers: 4)
Materials Horizons     Hybrid Journal   (Followers: 6)
Materials Research Bulletin     Hybrid Journal   (Followers: 25)
Materials Science-Poland     Open Access   (Followers: 1)
Materials Sciences and Applications     Open Access   (Followers: 2)
Medicinal Chemistry Research     Hybrid Journal   (Followers: 8)
Mediterranean Journal of Chemistry     Open Access  
Metallography, Microstructure, and Analysis     Hybrid Journal   (Followers: 1)
Micro and Nano Systems Letters     Open Access   (Followers: 6)
Microchimica Acta     Hybrid Journal   (Followers: 2)
Microporous and Mesoporous Materials     Hybrid Journal   (Followers: 9)
Modern Chemistry & Applications     Open Access   (Followers: 1)
Modern Research in Catalysis     Open Access  
Molbank     Open Access  
Molecular Catalysis     Hybrid Journal   (Followers: 5)
Molecules     Open Access   (Followers: 4)
Molecules and Cells     Hybrid Journal   (Followers: 1)
Monatshefte für Chemie - Chemical Monthly     Hybrid Journal   (Followers: 4)
Mongolian Journal of Chemistry     Open Access  
Moscow University Chemistry Bulletin     Hybrid Journal   (Followers: 1)
MRS Bulletin     Full-text available via subscription   (Followers: 4)
Nachrichten aus der Chemie     Hybrid Journal   (Followers: 13)
Nano Convergence     Open Access   (Followers: 1)
Nano Materials Science     Open Access   (Followers: 1)
Nano Reviews & Experiments     Open Access   (Followers: 14)
Nano Select     Open Access  
Nanochemistry Research     Open Access   (Followers: 1)
Nanoscale     Hybrid Journal   (Followers: 18)
Nanoscale Advances     Open Access  
Nanoscale Horizons     Hybrid Journal  
Nanoscale Research Letters     Open Access   (Followers: 8)
Nanoscience and Nanotechnology Letters     Full-text available via subscription   (Followers: 24)
Natural Product Communications     Open Access  
Natural Product Reports     Hybrid Journal   (Followers: 10)
Natural Science     Open Access   (Followers: 8)
Natural Volatiles & Essential Oils     Open Access  
Nature Chemistry     Full-text available via subscription   (Followers: 96)
Nature Protocols     Full-text available via subscription   (Followers: 73)
Nature Reviews Chemistry     Hybrid Journal   (Followers: 17)
New Journal of Chemistry     Hybrid Journal   (Followers: 16)
Nitric Oxide     Hybrid Journal  
Nitrogen     Open Access  
Nukleonika     Open Access  
Open Chemistry Journal     Open Access  
Open Conference Proceedings Journal     Open Access  
Open Journal of Chemistry     Open Access  
Open Journal of Composite Materials     Open Access   (Followers: 22)
Open Journal of Inorganic Non-metallic Materials     Open Access   (Followers: 2)
Open Journal of Medicinal Chemistry     Open Access   (Followers: 4)
Open Journal of Polymer Chemistry     Open Access   (Followers: 12)
Open Journal of Synthesis Theory and Applications     Open Access  
Open Medicinal Chemistry Journal     Open Access  
Orbital - The Electronic Journal of Chemistry     Open Access   (Followers: 1)
Organic & Biomolecular Chemistry     Hybrid Journal   (Followers: 55)
Organometallics     Hybrid Journal   (Followers: 18)
Oxidation of Metals     Hybrid Journal   (Followers: 16)
Passer Journal of Basic and Applied Sciences     Open Access  
Peptide Science     Full-text available via subscription  
Pharmaceuticals     Open Access   (Followers: 4)
Pharmaceutics     Open Access   (Followers: 5)
Phosphorus, Sulfur, and Silicon and the Related Elements     Hybrid Journal   (Followers: 2)
Photochemistry and Photobiology     Hybrid Journal   (Followers: 3)
Physical Science International Journal     Open Access  
Physics and Materials Chemistry     Open Access   (Followers: 1)
Phytochemistry     Hybrid Journal   (Followers: 4)
Phytochemistry Letters     Full-text available via subscription   (Followers: 1)
Plasma     Open Access   (Followers: 3)
Plasma Chemistry and Plasma Processing     Hybrid Journal   (Followers: 3)
Polycyclic Aromatic Compounds     Hybrid Journal  
Polyhedron     Hybrid Journal   (Followers: 4)
Polymer Chemistry     Hybrid Journal   (Followers: 24)
Polymer crystallization     Hybrid Journal  
Polymer Degradation and Stability     Hybrid Journal   (Followers: 23)
Polymer Engineering & Science     Hybrid Journal   (Followers: 14)
Polymer Reviews     Hybrid Journal   (Followers: 32)
Polymer Science Series D     Hybrid Journal   (Followers: 3)
Polymer Testing     Hybrid Journal   (Followers: 198)
Polymer-Plastics Technology and Materials     Hybrid Journal   (Followers: 5)
Polymers     Open Access   (Followers: 21)
Polymers from Renewable Resources     Hybrid Journal  
Proceedings of the Combustion Institute     Full-text available via subscription   (Followers: 8)
Processes     Open Access  
Progress in Lipid Research     Hybrid Journal   (Followers: 3)
Progress in Organic Coatings     Hybrid Journal   (Followers: 7)
Progress in Polymer Science     Full-text available via subscription   (Followers: 36)
Progress in Reaction Kinetics and Mechanism     Open Access  
Progress in Solid State Chemistry     Full-text available via subscription   (Followers: 3)
Progress in Surface Science     Full-text available via subscription   (Followers: 3)
Protein Science     Hybrid Journal   (Followers: 43)
Radiochemistry     Hybrid Journal   (Followers: 1)
Rapid Communications in Mass Spectrometry     Hybrid Journal   (Followers: 32)
Reaction Chemistry & Engineering     Hybrid Journal  
Reaction Kinetics, Mechanisms and Catalysis     Hybrid Journal   (Followers: 3)
Reactions     Open Access  
Reportes Científicos de la FaCEN     Open Access  
Research Journal of Phytochemistry     Open Access   (Followers: 1)
Resources Chemicals and Materials     Full-text available via subscription   (Followers: 5)
Results in Chemistry     Open Access  
Results in Geochemistry     Open Access  
Results in Surfaces and Interfaces     Open Access  
Review Journal of Chemistry     Hybrid Journal   (Followers: 1)
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Revista Boliviana de Química     Open Access  
Revista CENIC. Ciencias Quimicas     Open Access  
Revista Colombiana de Ciencias Químico-Farmacéuticas     Open Access  
Revista Colombiana de Química     Open Access  
Revista Cubana de Química     Open Access  
Revista de Ciencia y Tecnología     Open Access  
Revista de Ciencias     Open Access  
Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales     Open Access  
Revista de la Sociedad Química del Perú     Open Access  
Revista de la Societat Catalana de Química     Open Access  
Revista de Química     Open Access   (Followers: 6)
Revista Debates em Ensino de Química     Open Access  
Revista ION     Open Access  
RSC Advances     Open Access   (Followers: 27)
RSC Chemical Biology     Open Access  
RSC Medicinal Chemistry     Hybrid Journal   (Followers: 6)
Russian Journal of Bioorganic Chemistry     Hybrid Journal   (Followers: 1)
Russian Journal of Coordination Chemistry     Hybrid Journal   (Followers: 1)
Russian Journal of General Chemistry     Hybrid Journal   (Followers: 1)
Russian Journal of Inorganic Chemistry     Hybrid Journal  
Sainstek : Jurnal Sains dan Teknologi     Open Access  
Science China Chemistry     Hybrid Journal   (Followers: 2)
Science Talks     Full-text available via subscription   (Followers: 4)
Sciences & Technologie A : sciences exactes     Open Access  
Scientific Journal of Frontier Chemical Development     Open Access   (Followers: 2)

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Marine Drugs
Journal Prestige (SJR): 0.978
Citation Impact (citeScore): 5
Number of Followers: 1  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1660-3397
Published by MDPI Homepage  [84 journals]
  • Marine Drugs, Vol. 20, Pages 406: A Comprehensive Update on the Bioactive
           Compounds from Seagrasses

    • Authors: Christina Mutiara Putri Gono, Peni Ahmadi, Triana Hertiani, Eris Septiana, Masteria Yunovilsa Putra, Giuseppina Chianese
      First page: 406
      Abstract: Marine angiosperms produce a wide variety of secondary metabolites with unique structural features that have the potential to be developed as effective and potent drugs for various diseases. Recently, research trends in secondary metabolites have led to drug discovery with an emphasis on their pharmacological activity. Among marine angiosperms, seagrasses have been utilized for a variety of remedial purposes, such as treating fevers, mental disorders, wounds, skin diseases, muscle pain, and stomach problems. Hence, it is essential to study their bioactive metabolites, medical properties, and underlying mechanisms when considering their pharmacological activity. However, there is a scarcity of studies on the compilation of existing work on their pharmacological uses, pharmacological pathways, and bioactive compounds. This review aims to compile the pharmacological activities of numerous seagrass species, their secondary metabolites, pharmacological properties, and mechanism of action. In conclusion, this review highlights the potency of seagrasses as a promising source of natural therapeutical products for preventing or inhibiting human diseases.
      Citation: Marine Drugs
      PubDate: 2022-06-21
      DOI: 10.3390/md20070406
      Issue No: Vol. 20, No. 7 (2022)
  • Marine Drugs, Vol. 20, Pages 407: Chlorella vulgaris Extracts as
           Modulators of the Health Status and the Inflammatory Response of Gilthead
           Seabream Juveniles (Sparus aurata)

    • Authors: Bruno Reis, Lourenço Ramos-Pinto, Sara A. Cunha, Manuela Pintado, Joana Laranjeira da Silva, Jorge Dias, Luís Conceição, Elisabete Matos, Benjamín Costas
      First page: 407
      Abstract: This study aimed to evaluate the effects of short-term supplementation, with 2% Chlorella vulgaris (C. vulgaris) biomass and two 0.1% C. vulgaris extracts, on the health status (experiment one) and on the inflammatory response (experiment two) of gilthead seabream (Sparus aurata). The trial comprised four isoproteic (50% crude protein) and isolipidic (17% crude fat) diets. A fishmeal-based (FM), practical diet was used as a control (CTR), whereas three experimental diets based on CTR were further supplemented with a 2% inclusion of C. vulgaris biomass (Diet D1); 0.1% inclusion of C. vulgaris peptide-enriched extract (Diet D2) and finally a 0.1% inclusion of C. vulgaris insoluble fraction (Diet D3). Diets were randomly assigned to quadruplicate groups of 97 fish/tank (IBW: 33.4 ± 4.1 g), fed to satiation three times a day in a recirculation seawater system. In experiment one, seabream juveniles were fed for 2 weeks and sampled for tissues at 1 week and at the end of the feeding period. Afterwards, randomly selected fish from each group were subjected to an inflammatory insult (experiment two) by intraperitoneal injection of inactivated gram-negative bacteria, following 24 and 48 h fish were sampled for tissues. Blood was withdrawn for haematological procedures, whereas plasma and gut tissue were sampled for immune and oxidative stress parameters. The anterior gut was also collected for gene expression measurements. After 1 and 2 weeks of feeding, fish fed D2 showed higher circulating neutrophils than seabream fed CTR. In contrast, dietary treatments induced mild effects on the innate immune and antioxidant functions of gilthead seabream juveniles fed for 2 weeks. In the inflammatory response following the inflammatory insult, mild effects could be attributed to C. vulgaris supplementation either in biomass form or extract. However, the C. vulgaris soluble peptide-enriched extract seems to confer a protective, anti-stress effect in the gut at the molecular level, which should be further explored in future studies.
      Citation: Marine Drugs
      PubDate: 2022-06-21
      DOI: 10.3390/md20070407
      Issue No: Vol. 20, No. 7 (2022)
  • Marine Drugs, Vol. 20, Pages 339: Structure Revision of Penipacids
           A–E Reveals a Putative New Cryptic Natural Product,
           N-aminoanthranilic Acid, with Potential as a Transcriptional Regulator of
           Silent Secondary Metabolism

    • Authors: Zeinab G. Khalil, Sarani Kankanamge, Robert J. Capon
      First page: 339
      Abstract: Reconsideration of the spectroscopic data for penipacids A–E, first reported in 2013 as the acyclic amidines 1–5 from the South China deep sea sediment-derived fungus Penicillium paneum SD-44, prompted a total synthesis structure revision as the hydrazones 6–10. This revision strongly supported the proposition that penipacids A–B (6–7) were artifact Schiff base adducts of the cryptic (undetected) natural product N-aminoanthranilic acid (11) with diacetone alcohol, induced by excessive exposure to acetone and methanol under acidic handling conditions. Likewise, the revised structures for penipacids C–D (8–9) and E (10) raise the possibility that they may also be artifact Schiff base adducts of 11 and the media constituents pyruvic acid and furfural, respectively. A review of the natural products literature revealed other Schiff base (hydrazone) natural products that might also be viewed as Schiff base adduct artifacts of 11. Having raised the prospect that 11 is an undetected and reactive cryptic natural product, we went on to establish that 11 is not cytotoxic to a range of bacterial, fungal or mammalian (human) cell types. Instead, when added as a supplement to microbial cultivations, 11 can act as a chemical cue/transcriptional regulator, activating and/or enhancing the yield of biosynthetic gene clusters encoding for other natural product chemical defenses. This study demonstrates the value of challenging the structure and artifact status of natural products, as a window into the hidden world of cryptic and highly reactive natural products.
      Citation: Marine Drugs
      PubDate: 2022-05-24
      DOI: 10.3390/md20060339
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 340: Added Value of Ascophyllum nodosum Side
           Stream Utilization during Seaweed Meal Processing

    • Authors: Anna Þóra Hrólfsdóttir, Sigurjón Arason, Hildur Inga Sveinsdóttir, María Gudjónsdóttir
      First page: 340
      Abstract: Ascophyllum nodosum contains many valuable compounds, including polyphenols, peptides, and carotenoids that have been shown to exhibit biological activities. These compounds are not a priority ingredient in seaweed meal products for the current users. Hence, the aim of the study was to investigate the chemical and bioactive characteristics of A. nodosum as affected by seasonal variation and evaluate the potential benefits of alternative processing and the utilization of side streams for product development. The analysis of raw materials, press liquid, and press cake from alternative processing and the commercial seaweed meal at different harvesting periods indicated that the chemical composition is linked to the reproductive state of the algae. Phenolic content and ORAC activity increased following the seaweed’s fertile period, making alternative processing more promising in July and October compared to June. Several valuable ingredients were obtained in the press liquid, including polyphenols, which can be used in the development of new high-value bioactive products. The suggested alternative processing does not have a negative effect on the composition and quality of the current seaweed meal products. Hence, the extraction of valuable ingredients from the fresh biomass during the processing of seaweed meal could be a feasible option to increase the value and sustainability of seaweed processing.
      Citation: Marine Drugs
      PubDate: 2022-05-24
      DOI: 10.3390/md20060340
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 341: Recent Advances in the Heterologous
           Expression of Biosynthetic Gene Clusters for Marine Natural Products

    • Authors: Yushan Xu, Xinhua Du, Xionghui Yu, Qian Jiang, Kaiwen Zheng, Jinzhong Xu, Pinmei Wang
      First page: 341
      Abstract: Marine natural products (MNPs) are an important source of biologically active metabolites, particularly for therapeutic agent development after terrestrial plants and nonmarine microorganisms. Sequencing technologies have revealed that the number of biosynthetic gene clusters (BGCs) in marine microorganisms and the marine environment is much higher than expected. Unfortunately, the majority of them are silent or only weakly expressed under traditional laboratory culture conditions. Furthermore, the large proportion of marine microorganisms are either uncultivable or cannot be genetically manipulated. Efficient heterologous expression systems can activate cryptic BGCs and increase target compound yield, allowing researchers to explore more unknown MNPs. When developing heterologous expression of MNPs, it is critical to consider heterologous host selection as well as genetic manipulations for BGCs. In this review, we summarize current progress on the heterologous expression of MNPs as a reference for future research.
      Citation: Marine Drugs
      PubDate: 2022-05-24
      DOI: 10.3390/md20060341
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 342: Phytochemical and Potential Properties
           of Seaweeds and Their Recent Applications: A Review

    • Authors: Hossam S. El-Beltagi, Amal A. Mohamed, Heba I. Mohamed, Khaled M. A. Ramadan, Aminah A. Barqawi, Abdallah Tageldein Mansour
      First page: 342
      Abstract: Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.
      Citation: Marine Drugs
      PubDate: 2022-05-24
      DOI: 10.3390/md20060342
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 343: Assessment of Eicosapentaenoic Acid
           (EPA) Production from Filamentous Microalga Tribonema aequale: From
           Laboratory to Pilot-Scale Study

    • Authors: Jijian Long, Jing Jia, Yingchun Gong, Danxiang Han, Qiang Hu
      First page: 343
      Abstract: It has long been explored to use EPA-rich unicellular microalgae as a fish oil alternative for production of the high-value omega-3 fatty acid eicosapentaenoic acid (EPA, 20:5, n-3). However, none of the efforts have ever reached commercial success. This study reported a filamentous yellow-green microalga Tribonema aequale that possesses the ability to grow rapidly and synthesize significant amounts of EPA. A series of studies were conducted in a glass column photobioreactor under laboratory culture conditions and in pilot-scale open raceway ponds outdoors. The emphasis was placed on the specific nutrient requirements and the key operational parameters in raceway ponds such as culture depth and mixing regimes. When optimized, T. aequale cells contained 2.9% of EPA (w/w) and reached a very high biomass concentration of 9.8 g L−1 in the glass column photobioreactor. The cellular EPA content was increased further to 3.5% and the areal biomass and EPA productivities of 16.2 g m−2 d−1 and 542.5 mg m−2 d−1, respectively, were obtained from the outdoor pilot-scale open raceway ponds, which were the record high figures reported thus far from microalgae-based EPA production. It was also observed that T. aequale was highly resistant to microbial contamination and easy for harvesting and dewatering, which provide two additional competitive advantages of this filamentous microalga over the unicellular counterparts for potential commercial production of EPA and other derived co-products.
      Citation: Marine Drugs
      PubDate: 2022-05-24
      DOI: 10.3390/md20060343
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 344: A 3D-Printed Polycaprolactone/Marine
           Collagen Scaffold Reinforced with Carbonated Hydroxyapatite from Fish
           Bones for Bone Regeneration

    • Authors: Se-Chang Kim, Seong-Yeong Heo, Gun-Woo Oh, Myunggi Yi, Won-Kyo Jung
      First page: 344
      Abstract: In bone tissue regeneration, extracellular matrix (ECM) and bioceramics are important factors, because of their osteogenic potential and cell–matrix interactions. Surface modifications with hydrophilic material including proteins show significant potential in tissue engineering applications, because scaffolds are generally fabricated using synthetic polymers and bioceramics. In the present study, carbonated hydroxyapatite (CHA) and marine atelocollagen (MC) were extracted from the bones and skins, respectively, of Paralichthys olivaceus. The extracted CHA was characterized using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis, while MC was characterized using FTIR spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The scaffolds consisting of polycaprolactone (PCL), and different compositions of CHA (2.5%, 5%, and 10%) were fabricated using a three-axis plotting system and coated with 2% MC. Then, the MC3T3-E1 cells were seeded on the scaffolds to evaluate the osteogenic differentiation in vitro, and in vivo calvarial implantation of the scaffolds was performed to study bone tissue regeneration. The results of mineralization confirmed that the MC/PCL, 2.5% CHA/MC/PCL, 5% CHA/MC/PCL, and 10% CHA/MC/PCL scaffolds increased osteogenic differentiation by 302%, 858%, 970%, and 1044%, respectively, compared with pure PCL scaffolds. Consequently, these results suggest that CHA and MC obtained from byproducts of P. olivaceus are superior alternatives for land animal-derived substances.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060344
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 345: Antioxidative Effect of Chlorella
           Pyrenoidosa Protein Hydrolysates and Their Application in Krill
           Oil-in-Water Emulsions

    • Authors: Yujia Liu, Yuli Qi, Qi Wang, Fawen Yin, Honglei Zhan, Han Wang, Bingnan Liu, Yoshimasa Nakamura, Jihui Wang
      First page: 345
      Abstract: Chlorella pyrenoidosa is an excellent source of protein, and in this research, we assessed the antioxidant and emulsifying effects of Chlorella protein hydrolysate (CPH) using neutral proteases and alkaline proteases, as well as the properties of CPH-derived krill oil-in-water (O/W) emulsions. The CPHs exhibited the ability to scavenge several kinds of free radicals, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), O2−, hydroxyl, and ABTS. Additionally, the CPHs (5 mg/mL) scavenged approximately 100% of the DPPH and ABTS. The CPHs showed similar emulsifying activities to Tween 20 and excellent foaming activities (max FS 74%), which helped to stabilize the krill oil-in-water emulsion. Less than 10 mg/mL CPHs was able to form fresh krill oil-in-water emulsions; moreover, the CPHs (5 mg/mL) in a krill O/W emulsion were homogenous, opaque, and stable for at least 30 days. Based on their inhibitory effects on the peroxide value (POV) and thiobarbituric acid reactive substances (TRABS), the CPHs were found to be able to inhibit lipid oxidation in both emulsifying systems and krill O/W emulsions. Thus, the CPHs could improve superoxide dismutase (SOD) activities by 5- or 10-fold and decrease the high reactive oxygen species (ROS) level caused by the addition of H2O2 in vitro. In conclusion, health-promoting CPHs could be applied in krill oil-in-water emulsions as both emulsifiers and antioxidants, which could help to improve the oxidative and physical stability of emulsions.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060345
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 346: Utility of a Hydrolysate from
           Overproduced Paralichthys olivaceus for Hypertension Treatment:
           Correlation between Physical Properties and Potent Anti-Hypertensive

    • Authors: Hyo-Geun Lee, Jae-Young Oh, Dong-Min Chung, Min-Young Seo, Shin-Jae Park, You-Jin Jeon, Bo-Mi Ryu
      First page: 346
      Abstract: Aquacultured fish are the richest natural source of protein. However, their overproduced biomass is often discarded due to production imbalance, causing considerable losses to the fishery industry. Therefore, it is necessary to utilize surplus fish and add value to overproduced fish. We performed complex enzyme-assisted hydrolysis to determine the correlation between its physical characteristics and anti-hypertensive activity in vitro and in vivo using an SHR model. Protamex-Pepsin assisted hydrolysate from Paralichthys olivaceus (POppH) produced by complex enzyme-assisted hydrolysis contained low-molecular-weight peptides and amino acids with anti-hypertensive activity. POppH regulated blood pressure and serum angiotensin II and angiotensin-I-converting enzyme levels, and histological and ultrasound image analysis revealed substantially reduced thickness and diameter of the carotid aorta in the POppH-administered SHR group. Therefore, we propose to reduce food loss due to overproduction by utilizing the anti-hypertensive activity and physical properties of POppH; the results demonstrate its application as a therapeutic agent.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060346
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 347: Marine-Derived Xanthone from 2010 to
           2021: Isolation, Bioactivities and Total Synthesis

    • Authors: Ana C. S. Veríssimo, Diana C. G. A. Pinto, Artur M. S. Silva
      First page: 347
      Abstract: Marine life has proved to be an invaluable source of new compounds with significant bioactivities, such as xanthones. This review summarizes the advances made in the study of marine-derived xanthones from 2010 to 2021, from isolation towards synthesis, highlighting their biological activities. Most of these compounds were isolated from marine-derived fungi, found in marine sediments, and associated with other aquatic organisms (sponge and jellyfish). Once isolated, xanthones have been assessed for different bioactivities, such as antibacterial, antifungal, and cytotoxic properties. In the latter case, promising results have been demonstrated. Considering the significant bioactivities showed by xanthones, efforts have been made to synthesize these compounds, like yicathins B and C and the secalonic acid D, through total synthesis.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060347
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 348: Comparative Study on the Performance of
           Three Detection Methods for the Quantification of Pacific Ciguatoxins in
           French Polynesian Strains of Gambierdiscus polynesiensis

    • Authors: Hélène Taiana Darius, Taina Revel, Jérôme Viallon, Manoëlla Sibat, Philippe Cruchet, Sébastien Longo, Donnie Ransom Hardison, William C. Holland, Patricia A. Tester, R. Wayne Litaker, Jennifer R. McCall, Philipp Hess, Mireille Chinain
      First page: 348
      Abstract: Gambierdiscus and Fukuyoa dinoflagellates produce a suite of secondary metabolites, including ciguatoxins (CTXs), which bioaccumulate and are further biotransformed in fish and marine invertebrates, causing ciguatera poisoning when consumed by humans. This study is the first to compare the performance of the fluorescent receptor binding assay (fRBA), neuroblastoma cell-based assay (CBA-N2a), and liquid chromatography tandem mass spectrometry (LC-MS/MS) for the quantitative estimation of CTX contents in 30 samples, obtained from four French Polynesian strains of Gambierdiscus polynesiensis. fRBA was applied to Gambierdiscus matrix for the first time, and several parameters of the fRBA protocol were refined. Following liquid/liquid partitioning to separate CTXs from other algal compounds, the variability of CTX contents was estimated using these three methods in three independent experiments. All three assays were significantly correlated with each other, with the highest correlation coefficient (r2 = 0.841) found between fRBA and LC-MS/MS. The CBA-N2a was more sensitive than LC-MS/MS and fRBA, with all assays showing good repeatability. The combined use of fRBA and/or CBA-N2a for screening purposes and LC-MS/MS for confirmation purposes allows for efficient CTX evaluation in Gambierdiscus. These findings, which support future collaborative studies for the inter-laboratory validation of CTX detection methods, will help improve ciguatera risk assessment and management.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060348
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 349: Natural Marine Products: Anti-Colorectal
           Cancer In Vitro and In Vivo

    • Authors: Ningning Han, Jianjiang Li, Xia Li
      First page: 349
      Abstract: Colorectal cancer, a malignant tumor with high mortality, has a poor prognosis due to drug resistance and toxicity in clinical surgery and chemotherapy. Thus, finding safer and more efficient drugs for clinical trials is vital and urgent. Natural marine compounds, with rich resources and original chemical structures, are applied widely in anticancer treatments. We provide a systematic overview of recently reported marine compounds such as alkaloids, peptides, terpenoids, polysaccharides, and carotenoids from in vitro, in vivo, and clinical studies. The in vitro studies summarized the marine origins and pharmacological mechanisms, including anti-proliferation, anti-angiogenesis, anti-migration, anti-invasion, the acceleration of cycle arrest, and the promotion of tumor apoptosis, of various compounds. The in vivo studies outlined the antitumor effects of marine compounds on colorectal cancer model mice and evaluated their efficacy in terms of tumor inhibition, hepatotoxicity, and nephrotoxicity. The clinical studies summarized the major chemical classifications and targets of action of the clinical drugs that have entered clinical approval and completed approval for marine anticancer. In summary, we present the current situation regarding the application of natural anti-colorectal cancer marine compounds and prospects for their clinical application.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060349
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 350: Jellyfish as an Alternative Source of
           Bioactive Antiproliferative Compounds

    • Authors: Gennaro Riccio, Kevin A. Martinez, Jesús Martín, Fernando Reyes, Isabella D’Ambra, Chiara Lauritano
      First page: 350
      Abstract: Jellyfish are commonly considered a nuisance for their negative effects on human activities (e.g., fisheries, power plants and tourism) and human health. However, jellyfish provide several benefits to humans and are commonly eaten in eastern countries. Additionally, recent studies have suggested that jellyfish may become a source of high-value molecules. In this study, we tested the effects of the methanolic extracts and enriched fractions, obtained by solid-phase extraction fractionation, from the scyphomedusae Pelagia noctiluca, Rhizostoma pulmo, Cotylorhiza tuberculata and the cubomedusa Caryddea marsupialis on different human cancer cell lines in order to evaluate a potential antiproliferative activity. Our results indicated that fraction C from Caryddea marsupialis-(CM) and C. tuberculata oral arms (CTOA) were the most active to reduce cell viability in a dose-dependent manner. LC/MS based dereplication analyses highlighted that both bioactive fractions contained mainly fatty acids and derivatives, with CM additionally containing small peptides (0.7–0.8 kDa), which might contribute to its higher biological activity. The mechanism of action behind the most active fraction was investigated using PCR arrays. Results showed that the fraction C of CM can reduce the expression of genes involved in apoptosis inhibition in melanoma-treated cells, which makes jellyfish a potential new source of antiproliferative drugs to be exploited in the future.
      Citation: Marine Drugs
      PubDate: 2022-05-25
      DOI: 10.3390/md20060350
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 351: Nutrient Deprivation Coupled with High
           Light Exposure for Bioactive Chrysolaminarin Production in the Marine
           Microalga Isochrysis zhangjiangensis

    • Authors: Xiuyuan Ran, Yuhan Shen, Dongjian Jiang, Chenqi Wang, Xinghui Li, Haoyu Zhang, Yunyun Pan, Chenglin Xie, Tonghui Xie, Yongkui Zhang, Changhong Yao
      First page: 351
      Abstract: Chrysolaminarin, a kind of water-soluble bioactive β-glucan produced by certain microalgae, is a potential candidate for food/pharmaceutical applications. This study identified a marine microalga Isochrysis zhangjiangensis, in which chrysolaminarin production was investigated via nutrient (nitrogen, phosphorus, or sulfur) deprivations (-N, -P, or -S conditions) along with an increase in light intensity. A characterization of the antioxidant activities of the chrysolaminarin produced under each condition was also conducted. The results showed that nutrient deprivation caused a significant increase in chrysolaminarin accumulation, though this was accompanied by diminished biomass production and photosynthetic activity. -S was the best strategy to induce chrysolaminarin accumulation. An increase in light intensity from 80 (LL) to 150 (HL) µE·m−2·s−1 further enhanced chrysolaminarin production. Compared with –N, –S caused more suitable stress and reduced carbon allocation toward neutral lipid production, which enabled a higher chrysolaminarin accumulation capacity. The highest chrysolaminarin content and concentration reached 41.7% of dry weight (%DW) and 632.2 mg/L, respectively, under HL-S, with a corresponding productivity of 155.1 mg/L/day achieved, which exceeds most of the photoautotrophic microalgae previously reported. The chrysolaminarin produced under HL-N (Iz-N) had a relatively competitive hydroxyl radical scavenging activity at low concentrations, while the chrysolaminarin produced under HL-S (Iz-S) exhibited an overall better activity, comparable to the commercial yeast β-glucan, demonstrating I. zhangjiangensis as a promising bioactive chrysolaminarin producer from CO2.
      Citation: Marine Drugs
      PubDate: 2022-05-26
      DOI: 10.3390/md20060351
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 352: Marine Microbial-Derived Resource
           Exploration: Uncovering the Hidden Potential of Marine Carotenoids

    • Authors: Ray Steven, Zalfa Humaira, Yosua Natanael, Fenny M. Dwivany, Joko P. Trinugroho, Ari Dwijayanti, Tati Kristianti, Trina Ekawati Tallei, Talha Bin Emran, Heewon Jeon, Fahad A. Alhumaydhi, Ocky Karna Radjasa, Bonglee Kim
      First page: 352
      Abstract: Microbes in marine ecosystems are known to produce secondary metabolites. One of which are carotenoids, which have numerous industrial applications, hence their demand will continue to grow. This review highlights the recent research on natural carotenoids produced by marine microorganisms. We discuss the most recent screening approaches for discovering carotenoids, using in vitro methods such as culture-dependent and culture-independent screening, as well as in silico methods, using secondary metabolite Biosynthetic Gene Clusters (smBGCs), which involves the use of various rule-based and machine-learning-based bioinformatics tools. Following that, various carotenoids are addressed, along with their biological activities and metabolic processes involved in carotenoids biosynthesis. Finally, we cover the application of carotenoids in health and pharmaceutical industries, current carotenoids production system, and potential use of synthetic biology in carotenoids production.
      Citation: Marine Drugs
      PubDate: 2022-05-26
      DOI: 10.3390/md20060352
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 353: Antimicrobial and Immunoregulatory
           Activities of TS40, a Derived Peptide of a TFPI-2 Homologue from Black
           Rockfish (Sebastes schlegelii)

    • Authors: Hongmei Liu, Guanghua Wang, Dongfang Hao, Changbiao Wang, Min Zhang
      First page: 353
      Abstract: Tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine protease inhibitor. Previous reports have shown that TFPI-2 plays an important role in innate immunity, and the C-terminal region of TFPI-2 proved to be active against a broad-spectrum of microorganisms. In this study, the TFPI-2 homologue (SsTFPI-2) of black rockfish (Sebastods schegelii) was analyzed and characterized, and the biological functions of its C-terminal derived peptide TS40 (FVSRQSCMDVCAKGAKQHTSRGNVRRARRNRKNRITYLQA, corresponding to the amino acid sequence of 187-226) was investigated. The qRT-PCR (quantitative real-time reverse transcription-PCR) analysis showed that the expression of SsTFPI-2 was higher in the spleen and liver. The expression of SsTFPI-2 increased significantly under the stimulation of Listonella anguillarum. TS40 had a strong bactericidal effect on L. anguillarum and Staphylococcus aureus. Further studies found that TS40 can destroy the cell structure and enter the cytoplasm to interact with nucleic acids to exert its antibacterial activity. The in vivo study showed that TS40 treatment could significantly reduce the transmission of L. anguillarum and the viral evasion in fish. Finally, TS40 enhanced the respiratory burst ability, reactive oxygen species production and the expression of immune-related genes in macrophages, as well as promoted the proliferation of peripheral blood leukocytes. These results provide new insights into the role of teleost TFPI-2.
      Citation: Marine Drugs
      PubDate: 2022-05-26
      DOI: 10.3390/md20060353
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 354: Antihypertensive Effects of IGTGIPGIW
           Peptide Purified from Hippocampus abdominalis: p-eNOS and p-AKT

    • Authors: Hyo-Geun Lee, Hyun-Soo Kim, Hyesuck An, Kyunghwa Baek, Jeong Min Lee, Mi-Jin Yim, Seok-Chun Ko, Ji-Yul Kim, Gun-Woo Oh, Jun-Geon Je, Dae-Sung Lee, You-Jin Jeon
      First page: 354
      Abstract: The aim of this study was to assess the potential hypertensive effects of the IGTGIPGIW peptide purified from Hippocampus abdominalis alcalase hydrolysate (HA) for application in the functional food industry. We investigated the antihypertensive effects of IGTGIPGIW in vitro by assessing nitric oxide production in EA.hy926 endothelial cells, which is a major factor affecting vasorelaxation. The potential vasorelaxation effect was evaluated using 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate, a fluorescent stain. IGTGIPGIW significantly increased the expression of endothelial-derived relaxing factors, including endothelial nitric oxide synthase and protein kinase B, in EA.hy926 cells. Furthermore, oral administration of IGTGIPGIW significantly lowered the systolic blood pressure (183.60 ± 1.34 mmHg) and rapidly recovered the diastolic blood pressure (143.50 ± 5.55 mmHg) in the spontaneously hypertensive rat model in vivo. Our results demonstrate the antihypertensive activity of the IGTGIPGIW peptide purified from H. abdominalis and indicate its suitability for application in the functional food industry.
      Citation: Marine Drugs
      PubDate: 2022-05-26
      DOI: 10.3390/md20060354
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 355: Therapeutic Potential of
           Phlorotannin-Rich Ecklonia cava Extract on Methylglyoxal-Induced Diabetic
           Nephropathy in In Vitro Model

    • Authors: Chi-Heung Cho, Chang-Jun Lee, Min-Gyeong Kim, Bomi Ryu, Jun-Geon Je, Yoonsook Kim, Sang-Hoon Lee
      First page: 355
      Abstract: Advanced glycation end-products (AGEs) play a vital role in the pathogenesis of diabetic complications. Methylglyoxal (MGO), one of the major precursors of AGEs, is a highly reactive dicarbonyl compound that plays an important role in the pathogenesis of diabetic nephropathy. This study was designed to evaluate the therapeutic potential of phlorotannin-rich Ecklonia cava extract (ECE) on MGO-induced diabetic nephropathy in in vitro models using mouse glomerular mesangial cells. ECE showed anti-glycation activity via breaking of AGEs-collagen cross-links and inhibition of AGEs formation and AGE-collagen cross-linking formation. The renoprotective effects were determined by assessing intracellular reactive oxygen species (ROS) and MGO accumulation, cell apoptosis, and the Nrf-2/ARE signaling pathway. MGO-induced renal damage, intracellular ROS production level, and MGO-protein adduct accumulation were significantly decreased by pretreating ECE. Moreover, ECE pretreatment exhibited preventive properties against MGO-induced dicarbonyl stress via activation of the Nrf2/ARE signaling pathway and reduction of RAGE protein expression in mouse glomerular mesangial cells. Collectively, these results indicated potential anti-glycation properties and prominent preventive effects of ECE against MGO-induced renal damage. Additionally, ECE may be utilized for the management of AGE-related diabetic nephropathy.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060355
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 356: A Novel Bi-Functional Fibrinolytic
           Enzyme with Anticoagulant and Thrombolytic Activities from a
           Marine-Derived Fungus Aspergillus versicolor ZLH-1

    • Authors: Lihong Zhao, Xiuping Lin, Jingyun Fu, Jun Zhang, Wei Tang, Zengguo He
      First page: 356
      Abstract: Fibrinolytic enzymes are important components in the treatment of thrombosis-associated disorders. A new bi-functional fibrinolytic enzyme, versiase, was identified from a marine-derived fungus Aspergillus versicolor ZLH-1. The enzyme was isolated from the fungal culture through precipitation with ammonium sulfate at 90% saturation. Additionally, it was further purified by DEAE-based ion-exchange chromatography, with a recovery of 20.4%. The fibrinolytic enzyme presented as one band on both SDS-PAGE and fibrin-zymogram, with a molecular mass of 37.3 kDa. It was elucidated as a member of metalloprotease in M35 family by proteomic approaches. The homology-modeling analysis revealed that versiase shares significant structural homology wuth the zinc metalloendopeptidase. The enzyme displayed maximum activity at 40 °C and pH 5.0. The activity of versiase was strongly inhibited by the metalloprotease inhibitors EDTA and BGTA. Furthermore, versiase hydrolyzed fibrin directly and indirectly via the activation of plasminogen, and it was able to hydrolyze the three chains (α, β, γ) of fibrin(ogen). Additionally, versiase demonstrated promising thrombolytic and anticoagulant activities, without many side-effects noticed. In conclusion, versiase appears to be a potent fibrinolytic enzyme deserving further investigation.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060356
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 357: Subcritical Water Hydrolysis of Comb Pen
           Shell (Atrina pectinata) Edible Parts to Produce High-Value Amino Acid

    • Authors: Byung-Soo Chun, Seung-Chan Lee, Truc-Cong Ho, Jean-Bosco Micomyiza, Jin-Seok Park, Hee-Jeong Lee
      First page: 357
      Abstract: Artina pectinata (Comb pen shell, CPS) is a high-protein source that contains a variety of essential amino acids. Subcritical water hydrolysis (SWH) was used to recover amino acids from the posterior adductor muscle (PAM), anterior adductor muscle (ADM), and mantle. The temperatures ranged from 120 °C to 200 °C, and the pressure and time of hydrolysis were 3 MPa and 30 min, respectively. Further characterization of the hydrolysates was performed to ascertain amino acid profiles and biofunctional properties. The hydrolysates contained more free amino acids than the untreated samples. Antioxidant activity of treated samples increased as SW temperatures increased. At 200 °C, those inhibiting ACE had a maximum antihypertensive activity of 200 °C in 1% PAM, ADM, and mantle with 85.85 ± 0.67, 84.55 ± 0.18, and 82.15 ± 0.85%, respectively, compared to 97.57 ± 0.67% in 1% standard captopril. Perhaps the most significant finding was the predominance of taurine in the three parts following SW treatment at 120 °C. The hydrolysates may be of considerable interest for use in food or energy drinks. SWH demonstrates efficacy in recovering amino acids, particularly taurine, from edible parts of A. pectinata.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060357
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 358: Seaweed-Derived Polysaccharides
           Attenuate Heat Stress-Induced Splenic Oxidative Stress and Inflammatory
           Response via Regulating Nrf2 and NF-κB Signaling Pathways

    • Authors: Wen-Chao Liu, Di-Pai Zhuang, Yue Zhao, Balamuralikrishnan Balasubramanian, Zhi-Hui Zhao
      First page: 358
      Abstract: With global warming, heat stress (HS) has become a worldwide concern in both humans and animals. The ameliorative effect of seaweed (Enteromorpha prolifera) derived polysaccharides (SDP) on HS-induced oxidative stress and the inflammatory response of an immune organ (spleen) was evaluated using an animal model (Gallus gallus domesticus). In total, 144 animals were used in this 4-week trial and randomly assigned to the following three groups: thermoneutral zone, HS, and HS group supplemented with 1000 mg/kg SDP. Dietary SDP improved the antioxidant capacity and reduced the malondialdehyde (MDA) of the spleen when exposed to HS, regulated via enhancing nuclear factor erythroid 2-related factor-2 (Nrf2) signaling. Furthermore, the inclusion of SDP reduced the levels of pro-inflammatory cytokines and alleviated HS-induced splenic inflammatory response by suppressing the nuclear factor-kappa B (NF-κB) p65 signaling. These findings suggest that the SDP from E. prolifera can be used as a functional food and/or feed supplement to attenuate HS-induced oxidative stress and inflammatory responses of the immune organs. Moreover, the results could contribute to the development of high-value marine products from seaweed for potential use in humans and animals, owing to their antioxidant and anti-inflammatory effects.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060358
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 359: Sticking Together an Updated Model for
           Temporary Adhesion

    • Authors: Philip Bertemes, Alexandra L. Grosbusch, Anik Geschwindt, Bob Kauffmann, Willi Salvenmoser, Birte Mertens, Robert Pjeta, Bernhard Egger, Peter Ladurner
      First page: 359
      Abstract: Non-parasitic flatworms are known to temporarily attach to the substrate by secreting a multicomponent bioadhesive to counteract water movements. However, to date, only species of two higher-level flatworm taxa (Macrostomorpha and Proseriata) have been investigated for their adhesive proteins. Remarkably, the surface-binding protein is not conserved between flatworm taxa. In this study, we sequenced and assembled a draft genome, as well as a transcriptome, and generated a tail-specific positional RNA sequencing dataset of the polyclad Theama mediterranea. This led to the identification of 15 candidate genes potentially involved in temporary adhesion. Using in situ hybridisation and RNA interference, we determined their expression and function. Of these 15 genes, 4 are homologues of adhesion-related genes found in other flatworms. With this work, we provide two novel key components on the flatworm temporary adhesion system. First, we identified a Kringle-domain-containing protein (Tmed-krg1), which was expressed exclusively in the anchor cell. This in silico predicted membrane-bound Tmed-krg1 could potentially bind to the cohesive protein, and a knockdown led to a non-adhesive phenotype. Secondly, a secreted tyrosinase (Tmed-tyr1) was identified, which might crosslink the adhesive proteins. Overall, our findings will contribute to the future development of reversible synthetic glues with desirable properties for medical and industrial applications.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060359
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 360: Polyene Macrolactams from Marine and
           Terrestrial Sources: Structure, Production Strategies, Biosynthesis and

    • Authors: Wei Zhao, Hong Jiang, Xiao-Wan Liu, Jian Zhou, Bin Wu
      First page: 360
      Abstract: Over the past few decades (covering 1972 to 2022), astounding progress has been made in the elucidation of structures, bioactivities and biosynthesis of polyene macrolactams (PMLs), but they have only been partially summarized. PMLs possess a wide range of biological activities, particularly distinctive fungal inhibitory abilities, which render them a promising drug candidate. Moreover, the unique biosynthetic pathways including β-amino acid initiation and pericyclic reactions were presented in PMLs, leading to more attention from inside and outside the natural products community. According to current summation, in this review, the chem- and bio-diversity of PMLs from marine and terrestrial sources are considerably rich. A systematic, critical and comprehensive overview is in great need. This review described the PMLs’ general structural features, production strategies, biosynthetic pathways and the mechanisms of bioactivities. The challenges and opportunities for the research of PMLs are also discussed.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060360
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 361: Talaromarins A–F: Six New
           Isocoumarins from Mangrove-Derived Fungus Talaromyces flavus TGGP35

    • Authors: Jin Cai, Xiao-Chen Zhu, Wei-Nv Zeng, Bin Wang, You-Ping Luo, Jing Liu, Min-Jing Chen, Gao-Yu Li, Guo-Lei Huang, Guang-Ying Chen, Jing Xu, Cai-Juan Zheng
      First page: 361
      Abstract: Six new isocoumarin derivative talaromarins A-F (1–6), along with 17 known analogues (7–23), were isolated from the mangrove-derived fungus Talaromyces flavus (Eurotiales: Trichocomaceae) TGGP35. Their structures were identified by detailed IR, UV, 1D/2D NMR and HR-ESI-MS spectra. The absolute configurations of new compounds were determined by the modified Mosher’s method and a comparison of their CD spectra with dihydroisocoumarins described in the literature. The antioxidant, antibacterial, anti-phytopathogenic and inhibitory activity against α-glucosidase of all the isolated compounds were tested. Compounds 6–11, 17–19 and 21–22 showed similar or better antioxidant activity than the IC50 values ranging from 0.009 to 0.27 mM, compared with the positive control trolox (IC50 = 0.29 mM). Compounds 10, 18, 21 and 23 exhibited strong inhibitory activities against α-glucosidase with IC50 values ranging from 0.10 to 0.62 mM, while the positive control acarbose had an IC50 value of 0.5 mM. All compounds showed no antibacterial or anti-phytopathogenic activity at the concentrations of 50 μg/mL and 1 mg/mL, respectively. These results indicated that isocoumarins will be useful to developing antioxidants and as diabetes control agents.
      Citation: Marine Drugs
      PubDate: 2022-05-27
      DOI: 10.3390/md20060361
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 362: Biological Potential, Gastrointestinal
           Digestion, Absorption, and Bioavailability of Algae-Derived Compounds with
           Neuroprotective Activity: A Comprehensive Review

    • Authors: Bruna Martins, Mónica Vieira, Cristina Delerue-Matos, Clara Grosso, Cristina Soares
      First page: 362
      Abstract: Currently, there is no known cure for neurodegenerative disease. However, the available therapies aim to manage some of the symptoms of the disease. Human neurodegenerative diseases are a heterogeneous group of illnesses characterized by progressive loss of neuronal cells and nervous system dysfunction related to several mechanisms such as protein aggregation, neuroinflammation, oxidative stress, and neurotransmission dysfunction. Neuroprotective compounds are essential in the prevention and management of neurodegenerative diseases. This review will focus on the neurodegeneration mechanisms and the compounds (proteins, polyunsaturated fatty acids (PUFAs), polysaccharides, carotenoids, phycobiliproteins, phenolic compounds, among others) present in seaweeds that have shown in vivo and in vitro neuroprotective activity. Additionally, it will cover the recent findings on the neuroprotective effects of bioactive compounds from macroalgae, with a focus on their biological potential and possible mechanism of action, including microbiota modulation. Furthermore, gastrointestinal digestion, absorption, and bioavailability will be discussed. Moreover, the clinical trials using seaweed-based drugs or extracts to treat neurodegenerative disorders will be presented, showing the real potential and limitations that a specific metabolite or extract may have as a new therapeutic agent considering the recent approval of a seaweed-based drug to treat Alzheimer’s disease.
      Citation: Marine Drugs
      PubDate: 2022-05-28
      DOI: 10.3390/md20060362
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 363: The Immune System of Marine Organisms as
           Source for Drugs against Infectious Diseases

    • Authors: Alberto Falco, Mikolaj Adamek, Patricia Pereiro, David Hoole, José Antonio Encinar, Beatriz Novoa, Ricardo Mallavia
      First page: 363
      Abstract: The high proliferation of microorganisms in aquatic environments has allowed their coevolution for billions of years with other living beings that also inhabit these niches. Among the different existing types of interaction, the eternal competition for supremacy between the susceptible species and their pathogens has selected, as part of the effector division of the immune system of the former ones, a vast and varied arsenal of efficient antimicrobial molecules, which is highly amplified by the broad biodiversity radiated, above any others, at the marine habitats. At present, the great recent scientific and technological advances already allow the massive discovery and exploitation of these defense compounds for therapeutic purposes against infectious diseases of our interest. Among them, antimicrobial peptides and antimicrobial metabolites stand out because of the wide dimensions of their structural diversities, mechanisms of action, and target pathogen ranges. This revision work contextualizes the research in this field and serves as a presentation and scope identification of the Special Issue from Marine Drugs journal “The Immune System of Marine Organisms as Source for Drugs against Infectious Diseases”.
      Citation: Marine Drugs
      PubDate: 2022-05-28
      DOI: 10.3390/md20060363
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 364: Structures, Properties and Applications
           of Alginates

    • Authors: Roya Abka-khajouei, Latifa Tounsi, Nasim Shahabi, Anil Kumar Patel, Slim Abdelkafi, Philippe Michaud
      First page: 364
      Abstract: Alginate is a hydrocolloid from algae, specifically brown algae, which is a group that includes many of the seaweeds, like kelps and an extracellular polymer of some bacteria. Sodium alginate is one of the best-known members of the hydrogel group. The hydrogel is a water-swollen and cross-linked polymeric network produced by the simple reaction of one or more monomers. It has a linear (unbranched) structure based on d-mannuronic and l-guluronic acids. The placement of these monomers depending on the source of its production is alternating, sequential and random. The same arrangement of monomers can affect the physical and chemical properties of this polysaccharide. This polyuronide has a wide range of applications in various industries including the food industry, medicine, tissue engineering, wastewater treatment, the pharmaceutical industry and fuel. It is generally recognized as safe when used in accordance with good manufacturing or feeding practice. This review discusses its application in addition to its structural, physical, and chemical properties.
      Citation: Marine Drugs
      PubDate: 2022-05-29
      DOI: 10.3390/md20060364
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 365: Protein Hydrolysate from Spirulina
           platensis Prevents Dexamethasone-Induced Muscle Atrophy via Akt/Foxo3
           Signaling in C2C12 Myotubes

    • Authors: Chi-Woo Lee, Yeok Boo Chang, Chun Woong Park, Sung Hee Han, Hyung Joo Suh, Yejin Ahn
      First page: 365
      Abstract: Loss of muscle mass is the primary symptom of sarcopenia. Protein intake is recommended to prevent muscle mass loss, and Spirulina platensis, a microalga with high protein content, is a potential protein supplement. Here, we evaluated the differentiation ability of C2C12 cells and the inhibitory effect of Spirulina hydrolysates (SPH) prepared by Collupulin on dexamethasone (DEX)-treated C2C12 cells. SPH contained 578.27 mg/g protein and 92.30 mg/g branched-chain amino acids. SPH increased C2C12 myotube length and diameter, likely owing to increased MyoD1 and Myf5 expression. Inhibition of increased Atrogin-1, MuRF-1, and FoxO3 expression by SPH in DEX-treated C2C12 cells suppressed DEX-induced muscle atrophy. Moreover, SPH inhibited the DEX-induced increase in cytosolic p-Akt protein expression and suppressed the increase in nuclear FoxO3a protein expression, thereby suppressing the increase in the protein expression of the ubiquitin-proteasome-related factors Atrogin-1 and MuRF-1, which are involved in muscle atrophy. SPH suppressed DEX-induced muscle atrophy by activating the Akt/FoxO3a pathway. SPH promoted C2C12 myoblast differentiation into myotubes and inhibited DEX-induced myotube atrophy by suppressing Atrogin-1 and MuRF-1 expression and regulating the FoxO3a transcription factor. Collectively, SPH can be used as a functional food to inhibit muscle atrophy and promote muscle regeneration.
      Citation: Marine Drugs
      PubDate: 2022-05-29
      DOI: 10.3390/md20060365
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 366: Suitability of Marine- and
           Porcine-Derived Collagen Type I Hydrogels for Bioprinting and Tissue
           Engineering Scaffolds

    • Authors: Malachy Maher, Veronica Glattauer, Carmine Onofrillo, Serena Duchi, Zhilian Yue, Timothy C. Hughes, John A. M. Ramshaw, Gordon G. Wallace
      First page: 366
      Abstract: Collagens from a wide array of animals have been explored for use in tissue engineering in an effort to replicate the native extracellular environment of the body. Marine-derived biomaterials offer promise over their conventional mammalian counterparts due to lower risk of disease transfer as well as being compatible with more religious and ethical groups within society. Here, collagen type I derived from a marine source (Macruronus novaezelandiae, Blue Grenadier) is compared with the more established porcine collagen type I and its potential in tissue engineering examined. Both collagens were methacrylated, to allow for UV crosslinking during extrusion 3D printing. The materials were shown to be highly cytocompatible with L929 fibroblasts. The mechanical properties of the marine-derived collagen were generally lower than those of the porcine-derived collagen; however, the Young’s modulus for both collagens was shown to be tunable over a wide range. The marine-derived collagen was seen to be a potential biomaterial in tissue engineering; however, this may be limited due to its lower thermal stability at which point it degrades to gelatin.
      Citation: Marine Drugs
      PubDate: 2022-05-30
      DOI: 10.3390/md20060366
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 367: Evaluation of Cellular Uptake and
           Removal of Chlorpropham in the Treatment of Dunaliella salina for Phytoene

    • Authors: Laura Mazzucchi, Yanan Xu, Patricia J. Harvey
      First page: 367
      Abstract: Chlorpropham is a carbamate herbicide that inhibits cell division and has been widely used as a potato sprout suppressant. Recently we showed that the microalga Dunaliella salina treated with chlorpropham massively accumulated the colourless carotenoids phytoene and phytofluene. Phytoene and phytofluene are valued for their antioxidant, UV-absorption and skin protectant properties; however, they are present in very low quantities in nature. The low toxicity herbicide chlorpropham seems a promising catalyst to produce phytoene in large quantities from CO2 and solar energy with D. salina. This study explored chlorpropham uptake by the algal cells, the formation of potential intermediate metabolites, and the removal of residual chlorpropham from harvested D. salina biomass. Algal biomass rapidly concentrated chlorpropham from culture media. However, washing the harvested biomass with fresh culture medium twice and five times removed ~83 and ~97% of the chlorpropham from the biomass, respectively, and retained algal cell integrity. Furthermore, chloroaniline, a common metabolite of chlorpropham degradation, was not detected in chlorpropham-treated cultures, which were monitored every two days for thirty days. Cells treated with chlorpropham for either 10 min or 24 h continued to over-accumulate phytoene after resuspension in an herbicide-free medium. These data imply that whilst Dunaliella cells do not possess the intracellular capacity to degrade chlorpropham to chloroaniline, the effect of chlorpropham is irreversible on cell nuclear division and hence on carotenoid metabolism.
      Citation: Marine Drugs
      PubDate: 2022-05-30
      DOI: 10.3390/md20060367
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 368: Recent Advances in the Synthesis of
           Marine-Derived Alkaloids via Enzymatic Reactions

    • Authors: Bi-Shuang Chen, Di Zhang, Fayene Zeferino Ribeiro de Souza, Lan Liu
      First page: 368
      Abstract: Alkaloids are a large and structurally diverse group of marine-derived natural products. Most marine-derived alkaloids are biologically active and show promising applications in modern (agro)chemical, pharmaceutical, and fine chemical industries. Different approaches have been established to access these marine-derived alkaloids. Among these employed methods, biotechnological approaches, namely, (chemo)enzymatic synthesis, have significant potential for playing a central role in alkaloid production on an industrial scale. In this review, we discuss research progress on marine-derived alkaloid synthesis via enzymatic reactions and note the advantages and disadvantages of their applications for industrial production, as well as green chemistry for marine natural product research.
      Citation: Marine Drugs
      PubDate: 2022-05-30
      DOI: 10.3390/md20060368
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 369: Structures and Biologic Activity of
           Chitonoidosides I, J, K, K1 and L-Triterpene Di-, Tri- and Tetrasulfated
           Hexaosides from the Sea Cucumber Psolus chitonoides

    • Authors: Alexandra S. Silchenko, Sergey A. Avilov, Pelageya V. Andrijaschenko, Roman S. Popov, Ekaterina A. Chingizova, Pavel S. Dmitrenok, Anatoly I. Kalinovsky, Anton B. Rasin, Vladimir I. Kalinin
      First page: 369
      Abstract: Five new triterpene di-, tri- and tetrasulfated hexaosides (chitonoidosides I (1), J (2), K (3), K1 (4) and L (5)) were isolated from the Far-Eastern sea cucumber Psolus chitonoides, collected near Bering Island (Commander Islands) from a depth of 100–150 m. The structural variability of the glycosides concerned both the aglycones (with 7(8)- or 9(11)-double bonds) and carbohydrate chains differing from each other by the third sugar residue (Xyl or sulfated by C-6 Glc) and/or by the fourth—terminal in the bottom semi-chain—residue (Glc or sulfated by C-6 MeGlc) as well as by the positions of a sulfate group at C-4 or C-6 in the sixth—terminal in the upper semi-chain—residue (MeGlc). Hemolytic activities of these compounds 1–5 against human erythrocytes as well as cytotoxicity against human cancer cell lines, HeLa, DLD-1 and HL-60, were studied. The hexaosides, chitonoidosides K (3) and L (5) with four sulfate groups, were the most active against tumor cells in all the tests. Noticeably, the sulfate group at C-4 of MeGlc6 did not decrease the membranolytic effect of 5 as compared with 3, having the sulfate group at C-6 of MeGlc6. Erythrocytes were, as usual, more sensitive to the action of the studied glycosides than cancer cells, although the sensitivity of leukemia promyeloblast HL-60 cells was higher than that of other tumor cells. The glycosides 1 and 2 demonstrated some weaker action in relation to DLD-1 cells than against other tumor cell lines. Chitonoidoside K1 (4) with a hydroxyl at C 25 of the aglycone was not active in all the tests. The metabolic network formed by the carbohydrate chains of all the glycosides isolated from P. chitonoides as well as the aglycones biosynthetic transformations during their biosynthesis are discussed and illustrated with schemes.
      Citation: Marine Drugs
      PubDate: 2022-05-30
      DOI: 10.3390/md20060369
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 370: Fucoxanthin Is a Potential Therapeutic
           Agent for the Treatment of Breast Cancer

    • Authors: Tsz-Ying Lau, Hiu-Yee Kwan
      First page: 370
      Abstract: Breast cancer (BC) is one of the most common cancers diagnosed and the leading cause of cancer-related death in women. Although there are first-line treatments for BC, drug resistances and adverse events have been reported. Given the incidence of BC keeps increasing, seeking novel therapeutics is urgently needed. Fucoxanthin (Fx) is a dietary carotenoid commonly found in seaweeds and diatoms. Both in vitro and in vivo studies show that Fx and its deacetylated metabolite fucoxanthinol (Fxol) inhibit and prevent BC growth. The NF-κB signaling pathway is considered the major pathway contributing to the anti-proliferation, anti-angiogenesis and pro-apoptotic effects of Fx and Fxol. Other signaling molecules such as MAPK, MMP2/9, CYP and ROS are also involved in the anti-cancer effects by regulating the tumor microenvironment, cancer metastasis, carcinogen metabolism and oxidation. Besides, Fx also possesses anti-obesity effects by regulating UCP1 levels and lipid metabolism, which may help to reduce BC risk. More importantly, mounting evidence demonstrates that Fx overcomes drug resistance. This review aims to give an updated summary of the anti-cancer effects of Fx and summarize the underlying mechanisms of action, which will provide novel strategies for the development of Fx as an anti-cancer therapeutic agent.
      Citation: Marine Drugs
      PubDate: 2022-05-30
      DOI: 10.3390/md20060370
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 371: Identification of Volatiles of the
           Dinoflagellate Prorocentrum cordatum

    • Authors: Diana Koteska, Selene Sanchez Garcia, Irene Wagner-Döbler, Stefan Schulz
      First page: 371
      Abstract: The dinoflagellate Prorocentrum cordatum, often called P. minimum, is a potentially toxic alga found in algal blooms. Volatile compounds released by the alga might carry important information, e.g., on its physiological state, and may act as chemical messengers. We report here the identification of volatile organic compounds emitted by two strains, xenic P. cordatum CCMP 1529 and axenic P. cordatum CCMP 1329. The volatiles released during culture were identified despite their low production rates, using sensitive methods such as open-system-stripping analysis (OSSA) on Tenax TA desorption tubes, thermodesorption, cryofocusing and GC/MS-analysis. The analyses revealed 16 compounds released from the xenic strain and 52 compounds from the axenic strain. The majority of compounds were apocarotenoids, aromatic compounds and small oxylipins, but new natural products such as 3,7-dimethyl-4-octanolide were also identified and synthesized. The large difference of compound composition between xenic and axenic algae will be discussed.
      Citation: Marine Drugs
      PubDate: 2022-05-30
      DOI: 10.3390/md20060371
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 372: Characteristics of Marine Biomaterials
           and Their Applications in Biomedicine

    • Authors: Hengtong Zhang, Xixi Wu, Liang Quan, Qiang Ao
      First page: 372
      Abstract: Oceans have vast potential to develop high-value bioactive substances and biomaterials. In the past decades, many biomaterials have come from marine organisms, but due to the wide variety of organisms living in the oceans, the great diversity of marine-derived materials remains explored. The marine biomaterials that have been found and studied have excellent biological activity, unique chemical structure, good biocompatibility, low toxicity, and suitable degradation, and can be used as attractive tissue material engineering and regenerative medicine applications. In this review, we give an overview of the extraction and processing methods and chemical and biological characteristics of common marine polysaccharides and proteins. This review also briefly explains their important applications in anticancer, antiviral, drug delivery, tissue engineering, and other fields.
      Citation: Marine Drugs
      PubDate: 2022-05-31
      DOI: 10.3390/md20060372
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 373: The Development of the Bengamides as New
           Antibiotics against Drug-Resistant Bacteria

    • Authors: Cristina Porras-Alcalá, Federico Moya-Utrera, Miguel García-Castro, Antonio Sánchez-Ruiz, Juan Manuel López-Romero, María Soledad Pino-González, Amelia Díaz-Morilla, Seiya Kitamura, Dennis W. Wolan, José Prados, Consolación Melguizo, Iván Cheng-Sánchez, Francisco Sarabia
      First page: 373
      Abstract: The bengamides comprise an interesting family of natural products isolated from sponges belonging to the prolific Jaspidae family. Their outstanding antitumor properties, coupled with their unique mechanism of action and unprecedented molecular structures, have prompted an intense research activity directed towards their total syntheses, analogue design, and biological evaluations for their development as new anticancer agents. Together with these biological studies in cancer research, in recent years, the bengamides have been identified as potential antibiotics by their impressive biological activities against various drug-resistant bacteria such as Mycobacterium tuberculosis and Staphylococcus aureus. This review reports on the new advances in the chemistry and biology of the bengamides during the last years, paying special attention to their development as promising new antibiotics. Thus, the evolution of the bengamides from their initial exploration as antitumor agents up to their current status as antibiotics is described in detail, highlighting the manifold value of these marine natural products as valid hits in medicinal chemistry.
      Citation: Marine Drugs
      PubDate: 2022-05-31
      DOI: 10.3390/md20060373
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 374: Genus Nocardiopsis: A Prolific Producer
           of Natural Products

    • Authors: Ting Shi, Yi-Fei Wang, Han Wang, Bo Wang
      First page: 374
      Abstract: Actinomycetes are currently one of the major sources of bioactive secondary metabolites used for medicine development. Accumulating evidence has shown that Nocardiopsis, a key class of actinomycetes, has the ability to produce novel bioactive natural products. This review covers the sources, distribution, bioactivities, biosynthesis, and structural characteristics of compounds isolated from Nocardiopsis in the period between March 2018 and 2021. Our results reveal that 67% of Nocardiopsis-derived natural products are reported for the first time, and 73% of them are isolated from marine Nocardiopsis. The chemical structures of the Nocardiopsis-derived compounds have diverse skeletons, concentrating on the categories of polyketides, peptides, terphenyls, and alkaloids. Almost 50% of the natural products isolated from Nocardiopsis have been discovered to display various bioactivities. These results fully demonstrate the great potential of the genus Nocardiopsis to produce novel bioactive secondary metabolites that may serve as a structural foundation for the development of novel drugs.
      Citation: Marine Drugs
      PubDate: 2022-05-31
      DOI: 10.3390/md20060374
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 375: Xenoacremones D–H, Bioactive
           Tyrosine-decahydrofluorene Analogues from the Plant-Derived Fungus
           Xenoacremonium sinensis

    • Authors: Zhiguo Liu, Li Liu, Anqi Wang, Li Li, Sinan Zhao, Yanan Wang, Yi Sun
      First page: 375
      Abstract: Five novel tyrosine-decahydrofluorene analogues, xenoacremones D–H (1–5), each bearing a fused 6/5/6 tricarbocyclic core and a 13-membered para-cyclophane ring system, were isolated from the endophytic fungus Xenoacremonium sinensis. Compound 1 was a novel polyketide synthase–nonribosomal peptide synthetase (PKS–NRPS) tyrosine-decahydrofluorene hybrid containing a 6/5/6/6/5 ring system. Their structures were elucidated from comprehensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. All compounds were evaluated for their inhibitory activities on LPS-induced NO production in macrophages and their cytotoxicities against the NB4 and U937 cell lines. Compounds 3 and 5 exhibited potent anti-inflammatory activities in vitro. Compound 1 and 3–5 displayed significant antiproliferative activity against the tumor cell lines (IC50 < 20 µM).
      Citation: Marine Drugs
      PubDate: 2022-05-31
      DOI: 10.3390/md20060375
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 376: Comparison of Physicochemical and
           Structural Properties of Acid-Soluble and Pepsin-Soluble Collagens from
           Blacktip Reef Shark Skin

    • Authors: Baolin Ge, Chunyu Hou, Bin Bao, Zhilin Pan, José Eduardo Maté Sánchez de Val, Jeevithan Elango, Wenhui Wu
      First page: 376
      Abstract: Fish collagen has been widely used in tissue engineering (TE) applications as an implant, which is generally transplanted into target tissue with stem cells for better regeneration ability. In this case, the success rate of this research depends on the fundamental components of fish collagen such as amino acid composition, structural and rheological properties. Therefore, researchers have been trying to find an innovative raw material from marine origins for tissue engineering applications. Based on this concept, collagens such as acid-soluble (ASC) and pepsin-soluble (PSC) were extracted from a new type of cartilaginous fish, the blacktip reef shark, for the first time, and were further investigated for physicochemical, protein pattern, microstructural and peptide mapping. The study results confirmed that the extracted collagens resemble the protein pattern of type-I collagen comprising the α1, α2, β and γ chains. The hydrophobic amino acids were dominant in both collagens with glycine and hydroxyproline as major amino acids. From the FTIR spectra, α helix (27.72 and 26.32%), β-sheet (22.24 and 23.35%), β-turn (21.34 and 22.08%), triple helix (14.11 and 14.13%) and random coil (14.59 and 14.12%) structures of ASC and PSC were confirmed, respectively. Collagens retained their triple helical and secondary structure well. Both collagens had maximum solubility at 3% NaCl and pH 4, and had absorbance maxima at 234 nm, respectively. The peptide mapping was almost similar for ASC and PSC at pH 2, generating peptides ranging from 15 to 200 kDa, with 23 kDa as a major peptide fragment. The microstructural analysis confirmed the homogenous fibrillar nature of collagens with more interconnected networks. Overall, the preset study concluded that collagen can be extracted more efficiently without disturbing the secondary structure by pepsin treatment. Therefore, the blacktip reef shark skin could serve as a potential source for collagen extraction for the pharmaceutical and biomedical applications.
      Citation: Marine Drugs
      PubDate: 2022-06-02
      DOI: 10.3390/md20060376
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 377: A Fucan Sulfate with Pentasaccharide
           Repeating Units from the Sea Cucumber Holothuriafloridana and Its
           Anticoagulant Activity

    • Authors: Zimo Ning, Pin Wang, Zhichuang Zuo, Xuelin Tao, Li Gao, Chen Xu, Zhiyue Wang, Bin Wu, Na Gao, Jinhua Zhao
      First page: 377
      Abstract: A fucan sulfate (HfFS) was isolated from the sea cucumber Holothuriafloridana after proteolysis-alkaline treatment and purified with anion-exchange chromatography. The molecular weight (Mw) of HfFS was determined to be 443.4 kDa, and the sulfate content of HfFS was 30.4%. The structural analysis of the peroxidative depolymerized product (dHfFS-1) showed that the primary structure of HfFS was mainly composed of a distinct pentasaccharide repeating unit -[l-Fuc2S4S-α(1,3)-l-Fuc-α(1,3)-Fuc-α(1,3)-l-Fuc2S-α(1,3)-l-Fuc2S-α(1,3)-]n-. Then, the “bottom-up” strategy was employed to confirm the structure of HfFS, and a series of fucooligosaccharides (disaccharides, trisaccharides, and tetrasaccharides) were purified from the mild acid-hydrolyzed HfFS. The structures identified through 1D/2D NMR spectra showed that these fucooligosaccharides could be derivates from the pentasaccharide units, while the irregular sulfate substituent also exists in the units. Anticoagulant activity assays of native HfFS and its depolymerized products (dHf-1~dHf-6) in vitro suggested that HfFS exhibits potent APTT-prolonging activity and the potencies decreased with the reduction in molecular weights, and HfFS fragments (dHf-4~dHf-6) with Mw less than 11.5 kDa showed no significant anticoagulant effect. Overall, our study enriched the knowledge about the structural diversity of FSs in different sea cucumber species and their biological activities.
      Citation: Marine Drugs
      PubDate: 2022-06-03
      DOI: 10.3390/md20060377
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 378: Oncolytic Vaccinia Virus Harboring
           Aphrocallistes vastus Lectin Inhibits the Growth of Hepatocellular
           Carcinoma Cells

    • Authors: Riqing Jiang, Yufeng Qiu, Xiaomei Zhang, Ningning Zhou, Xiaoyuan Jia, Kan Chen, Yanrong Zhou, Ting Ye, Gongchu Li
      First page: 378
      Abstract: Oncolytic vaccinia virus has been developed as a novel cancer therapeutic drug in recent years. Our previous studies demonstrated that the antitumor effect of oncolytic vaccina virus harboring Aphrocallistes vastus lectin (oncoVV-AVL) was significantly enhanced in several cancer cells. In the present study, we investigated the underlying mechanisms of AVL that affect virus replication and promote the antitumor efficacy of oncolytic virus in hepatocellular carcinoma (HCC). Our results showed that oncoVV-AVL markedly exhibited antitumor effects in both hepatocellular carcinoma cell lines and a xenograft mouse model. Further investigation illustrated that oncoVV-AVL could activate tumor immunity by upregulating the expression of type I interferons and enhance virus replication by inhibiting ISRE mediated viral defense response. In addition, we inferred that AVL promoted the ability of virus replication by regulating the PI3K/Akt, MAPK/ERK, and Hippo/MST pathways through cross-talk Raf-1, as well as metabolism-related pathways. These findings provide a novel perspective for the exploitation of marine lectins in oncolytic therapy.
      Citation: Marine Drugs
      PubDate: 2022-06-04
      DOI: 10.3390/md20060378
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 379: Photoinduced Synthesis of Methylated
           Marine Cyclopeptide Galaxamide Analogs with Isoindolinone as Anticancer

    • Authors: Shimei Xiao, Zhiqiang Wang, Huanli Zhang, Lei Zhao, Qingran Chang, Xiong Zhang, Rui Yan, Xiaodan Wu, Yingxue Jin
      First page: 379
      Abstract: The methylation of amino acid residues has played an important role in the biological function of bioactive peptides. In this paper, various methyl-modified and stereostructural-modified marine cyclopeptide galaxamide analogs with isoindolinone were synthesized by a photoinduced single electron transfer cyclization reaction. It was found that the single-methyl substitution was beneficial for the bioactivity of cyclic analogs with isoindolinone fragments, and the influence of methylation on bioactivity is uncertain and is sometimes case-specific. The compound with a single methyl group at Gly5 (compound 8) showed the strongest antiproliferative activity against HepG-2 cells. The tumor cell apoptosis, cell cycle, mitochondrial membrane potential, intracellular Ca2+ concentration and lactate dehydrogenase activity have been studied extensively to evaluate the antitumor potential of compound 8. Western blotting tests showed that compound 8 could decrease the MDM2 level and increase p53 levels efficiently. Careful molecular docking suggested that cyclic peptide 8 could bind firmly with MDM2 oncoprotein, indicating that MDM2 may be a potential drug target of the prepared peptides.
      Citation: Marine Drugs
      PubDate: 2022-06-05
      DOI: 10.3390/md20060379
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 380: Fucose-Rich Sulfated Polysaccharides
           from Two Vietnamese Sea Cucumbers Bohadschia Argus and Holothuria
           (Theelothuria) Spinifera: Structures and Anticoagulant Activity

    • Authors: Nadezhda E. Ustyuzhanina, Maria I. Bilan, Andrey S. Dmitrenok, Eugenia A. Tsvetkova, Sofya P. Nikogosova, Cao Thi Thuy Hang, Pham Duc Thinh, Dinh Thanh Trung, Tran Thi Thanh Van, Alexander S. Shashkov, Anatolii I. Usov, Nikolay E. Nifantiev
      First page: 380
      Abstract: Fucosylated chondroitin sulfates (FCSs) FCS-BA and FCS-HS, as well as fucan sulfates (FSs) FS-BA-AT and FS-HS-AT were isolated from the sea cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera, respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-β-d-GalNAc-(1→4)-β-d-GlcA-(1→]n bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: FCS-BA contained Fuc2S4S, Fuc3S4S and Fuc4S at a ratio of 1:8:2, while FCS-HS contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc4S6S and GalNAc4S units, the ratios being 14:1 for FCS-BA and 4:1 for FCS-HS. Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. FS-BA-AT was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, FS-BA-AT was practically devoid of anticoagulant activity. FS-HS-AT cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with FS-BA-AT and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues.
      Citation: Marine Drugs
      PubDate: 2022-06-06
      DOI: 10.3390/md20060380
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 381: New Cladiellin-Type Diterpenoids from
           the South China Sea Soft Coral Cladiella krempfi: Structures and Molecular
           Docking Analysis in EGFRs

    • Authors: Yang Jin, Li-Gong Yao, Yue-Wei Guo, Xu-Wen Li
      First page: 381
      Abstract: Two new cladiellin-type diterpenoids (1 and 2) and four known related compounds 3–6, were isolated from the South China Sea soft coral Cladiella krempfi. Compound 2 is the third example of cladiellins of an unusual peroxy group in the C-6 position in C. krempfi. The structures and absolute configurations of the new compounds were established by extensive spectroscopic analysis, X-ray diffraction, and/or chemical correlation. In bioassay, all the compounds were evaluated for cytotoxicity and epidermal growth factor receptor (EGFR) inhibitory activity. A molecular docking experiment was conducted to study the structure–activity relationship of cladiellin-type diterpenoids on EGFR inhibitory activity.
      Citation: Marine Drugs
      PubDate: 2022-06-07
      DOI: 10.3390/md20060381
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 382: Increased Sulfation in Gracilaria
           fisheri Sulfated Galactans Enhances Antioxidant and Antiurolithiatic
           Activities and Protects HK-2 Cell Death Induced by Sodium Oxalate

    • Authors: Waraporn Sakaew, Jenjiralai Phanphak, Somsuda Somintara, Wiphawi Hipkaeo, Kanokpan Wongprasert, José Kovensky, Choowadee Pariwatthanakun, Tawut Rudtanatip
      First page: 382
      Abstract: Urolithiasis is a common urological disease characterized by the presence of a stone anywhere along the urinary tract. The major component of such stones is calcium oxalate, and reactive oxygen species act as an essential mediator of calcium oxalate crystallization. Previous studies have demonstrated the antioxidant and antiurolithiatic activities of sulfated polysaccharides. In this study, native sulfated galactans (N-SGs) with a molecular weight of 217.4 kDa from Gracilaria fisheri were modified to obtain lower molecular weight SG (L-SG) and also subjected to sulfation SG (S-SG). The in vitro antioxidant and antiurolithiatic activities of the modified substances and their ability to protect against sodium oxalate-induced renal tubular (HK-2) cell death were investigated. The results revealed that S-SG showed more pronounced antioxidant activities (DPPH and O2− scavenging activities) than those of other compounds. S-SG exhibited the highest antiurolithiatic activity in terms of nucleation and aggregation, as well as crystal morphology and size. Moreover, S-SG showed improved cell survival and increased anti-apoptotic BCL-2 protein in HK-2 cells treated with sodium oxalate. Our findings highlight the potential application of S-SG in the functional food and pharmaceutical industries.
      Citation: Marine Drugs
      PubDate: 2022-06-07
      DOI: 10.3390/md20060382
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 383: Marine Chitooligosaccharide Alters
           Intestinal Flora Structure and Regulates Hepatic Inflammatory Response to
           Influence Nonalcoholic Fatty Liver Disease

    • Authors: Jiayao Feng, Yongjian Liu, Jiajia Chen, Yan Bai, Jincan He, Hua Cao, Qishi Che, Jiao Guo, Zhengquan Su
      First page: 383
      Abstract: In this study, C57BL/6 mice were given an HFHSD diet for 8 weeks to induce hepatic steatosis and then given COSM solution orally for 12 weeks. The study found that the HFHSD diet resulted in steatosis and insulin resistance in mice. The formation of NAFLD induced by HFHSD diet was related to the imbalance of intestinal flora. However, after COSM intervention, the abundance of beneficial bacteria increased significantly, while the abundance of harmful bacteria decreased significantly. The HFHSD diet also induced changes in intestinal bacterial metabolites, and the content of short-chain fatty acids in cecal contents after COSM intervention was significantly higher than that in the model group. In addition, COSM not only improved LPS levels and barrier dysfunction in the ileum and colon but upregulated protein levels of ZO-1, occludin, and claudin in the colon and downregulated the liver LPS/TLR4/NF-κB inflammatory pathway. We concluded that the treatment of marine chitooligosaccharide COSM could improve the intestinal microflora structure of the fatty liver and activate an inflammatory signaling pathway, thus alleviating the intrahepatic lipid accumulation induced by HFHSD.
      Citation: Marine Drugs
      PubDate: 2022-06-07
      DOI: 10.3390/md20060383
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 384: Seaweed-Derived Phlorotannins: A Review
           of Multiple Biological Roles and Action Mechanisms

    • Authors: Fazlurrahman Khan, Geum-Jae Jeong, Mohd Sajjad Ahmad Khan, Nazia Tabassum, Young-Mog Kim
      First page: 384
      Abstract: Phlorotannins are a group of phenolic secondary metabolites isolated from a variety of brown algal species belonging to the Fucaceae, Sargassaceae, and Alariaceae families. The isolation of phlorotannins from various algal species has received a lot of interest owing to the fact that they have a range of biological features and are very biocompatible in their applications. Phlorotannins have a wide range of therapeutic biological actions, including antimicrobial, antidiabetic, antioxidant, anticancer, anti-inflammatory, anti-adipogenesis, and numerous other biomedical applications. The current review has extensively addressed the application of phlorotannins, which have been extensively investigated for the above-mentioned biological action and the underlying mechanism of action. Furthermore, the current review offers many ways to use phlorotannins to avoid certain downsides, such as low stability. This review article will assist the scientific community in investigating the greater biological significance of phlorotannins and developing innovative techniques for treating both infectious and non-infectious diseases in humans.
      Citation: Marine Drugs
      PubDate: 2022-06-08
      DOI: 10.3390/md20060384
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 385: Antiviral Activity and Mechanisms of
           Seaweeds Bioactive Compounds on Enveloped Viruses—A Review

    • Authors: Silvia Lomartire, Ana M. M. Gonçalves
      First page: 385
      Abstract: In the last decades, the interest in seaweed has significantly increased. Bioactive compounds from seaweed’s currently receive major attention from pharmaceutical companies as they express several interesting biological activities which are beneficial for humans. The structural diversity of seaweed metabolites provides diverse biological activities which are expressed through diverse mechanisms of actions. This review mainly focuses on the antiviral activity of seaweed’s extracts, highlighting the mechanisms of actions of some seaweed molecules against infection caused by different types of enveloped viruses: influenza, Lentivirus (HIV-1), Herpes viruses, and coronaviruses. Seaweed metabolites with antiviral properties can act trough different pathways by increasing the host’s defense system or through targeting and blocking virus replication before it enters host cells. Several studies have already established the large antiviral spectrum of seaweed’s bioactive compounds. Throughout this review, antiviral mechanisms and medical applications of seaweed’s bioactive compounds are analyzed, suggesting seaweed’s potential source of antiviral compounds for the formulation of novel and natural antiviral drugs.
      Citation: Marine Drugs
      PubDate: 2022-06-08
      DOI: 10.3390/md20060385
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 386: Antitumor Potential of Immunomodulatory
           Natural Products

    • Authors: Genoveffa Nuzzo, Giuseppina Senese, Carmela Gallo, Federica Albiani, Lucia Romano, Giuliana d’Ippolito, Emiliano Manzo, Angelo Fontana
      First page: 386
      Abstract: Cancer is one of the leading causes of death globally. Anticancer drugs aim to block tumor growth by killing cancerous cells in order to prevent tumor progression and metastasis. Efficient anticancer drugs should also minimize general toxicity towards organs and healthy cells. Tumor growth can also be successfully restrained by targeting and modulating immune response. Cancer immunotherapy is assuming a growing relevance in the fight against cancer and has recently aroused much interest for its wider safety and the capability to complement conventional chemotherapeutic approaches. Natural products are a traditional source of molecules with relevant potential in the pharmacological field. The huge structural diversity of metabolites with low molecular weight (small molecules) from terrestrial and marine organisms has provided lead compounds for the discovery of many modern anticancer drugs. Many natural products combine chemo-protective and immunomodulant activity, thus offering the potential to be used alone or in association with conventional cancer therapy. In this review, we report the natural products known to possess antitumor properties by interaction with immune system, as well as discuss the possible immunomodulatory mechanisms of these molecules.
      Citation: Marine Drugs
      PubDate: 2022-06-08
      DOI: 10.3390/md20060386
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 387: Call the Eckols: Present and Future
           Potential Cancer Therapies

    • Authors: Pedro Monteiro, Silvia Lomartire, João Cotas, João C. Marques, Leonel Pereira, Ana M. M. Gonçalves
      First page: 387
      Abstract: In recent years, an increased interest in marine macroalgae bioactive compounds has been recorded due to their benefits to human health and welfare. Several of their bioactivities have been demonstrated, such as anti-inflammatory, antioxidant, anticarcinogenic, antibacterial and antiviral behavior. However, there still lacks a clear definition regarding how these compounds exert their bioactive properties. Of all the bioactive compounds derived from marine macroalgae, attention has been focused on phenolic compounds, specifically in phlorotannins, due to their potential for biomedical applications. Phlorotannins are a diverse and wide group of phenolic compounds, with several structural variations based on the monomer phloroglucinol. Among the diverse phlorotannin structures, the eckol-family of phlorotannins demonstrates remarkable bioactivity, notably their anti-tumoral properties. However, the molecular mechanisms by which this activity is achieved remain elusive and sparse. This review focuses on the described molecular mechanisms of anti-tumoral effects by the eckol family of compounds and the future prospects of these molecules for potential application in oncology therapies.
      Citation: Marine Drugs
      PubDate: 2022-06-09
      DOI: 10.3390/md20060387
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 388: Genome Analysis of a Novel
           Polysaccharide-Degrading Bacterium Paenibacillus algicola and
           Determination of Alginate Lyases

    • Authors: Huiqin Huang, Zhiguo Zheng, Xiaoxiao Zou, Zixu Wang, Rong Gao, Jun Zhu, Yonghua Hu, Shixiang Bao
      First page: 388
      Abstract: Carbohydrate-active enzymes (CAZymes) are an important characteristic of bacteria in marine systems. We herein describe the CAZymes of Paenibacillus algicola HB172198T, a novel type species isolated from brown algae in Qishui Bay, Hainan, China. The genome of strain HB172198T is a 4,475,055 bp circular chromosome with an average GC content of 51.2%. Analysis of the nucleotide sequences of the predicted genes shows that strain HB172198T encodes 191 CAZymes. Abundant putative enzymes involved in the degradation of polysaccharides were identified, such as alginate lyase, agarase, carrageenase, xanthanase, xylanase, amylases, cellulase, chitinase, fucosidase and glucanase. Four of the putative polysaccharide lyases from families 7, 15 and 38 were involved in alginate degradation. The alginate lyases of strain HB172198T exhibited the maximum activity 152 U/mL at 50 °C and pH 8.0, and were relatively stable at pH 7.0 and temperatures lower than 40 °C. The average degree of polymerization (DP) of the sodium alginate oligosaccharide (AOS) degraded by the partially purified alginate lyases remained around 14.2, and the thin layer chromatography (TCL) analysis indicated that it contained DP2-DP8 oligosaccharides. The complete genome sequence of P. algicola HB172198T will enrich our knowledge of the mechanism of polysaccharide lyase production and provide insights into its potential applications in the degradation of polysaccharides such as alginate.
      Citation: Marine Drugs
      PubDate: 2022-06-09
      DOI: 10.3390/md20060388
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 389: Updated Trends on the Biodiscovery of
           New Marine Natural Products from Invertebrates

    • Authors: Ricardo Calado, Renato Mamede, Sónia Cruz, Miguel C. Leal
      First page: 389
      Abstract: From 1990–2019, a total of 15,442 New Marine Natural Products from Invertebrates (NMNPIs) were reported. The 2010s saw the most prolific decade of biodiscovery, with 5630 NMNPIs recorded. The phyla that contributed most biomolecules were the Porifera (sponges) (47.2%, 2659 NMNPIs) and the Cnidaria (35.3%, 1989 NMNPIs). The prevalence of these two phyla as the main sources of NMNPIs became more pronounced in the 2010s. The tropical areas of the Pacific Ocean yielded more NMNPIs, most likely due to the remarkable biodiversity of coral reefs. The Indo-Burma biodiversity hotspot (BH) was the most relevant area for the biodiscovery of NMNPIs in the 2010s, accounting for nearly one-third (1819 NMNPIs) of the total and surpassing the top BH from the 1990s and the 2000s (the Sea of Japan and the Caribbean Islands, respectively). The Chinese exclusive economic zone (EEZ) alone contributed nearly one-quarter (24.7%) of all NMNPIs recorded during the 2010s, displacing Japan’s leading role from the 1990s and the 2000s. With the biodiscovery of these biomolecules steadily decreasing since 2012, it is uncertain whether this decline has been caused by lower bioprospecting efforts or the potential exhaustion of chemodiversity from traditional marine invertebrate sources.
      Citation: Marine Drugs
      PubDate: 2022-06-09
      DOI: 10.3390/md20060389
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 390: A Paternal Fish Oil Diet Preconception
           Modulates the Gut Microbiome and Attenuates Necrotizing Enterocolitis in
           Neonatal Mice

    • Authors: Jelonia T. Rumph, Victoria R. Stephens, Sharareh Ameli, Philip N. Gaines, Kevin G. Osteen, Kaylon L. Bruner-Tran, Pius N. Nde
      First page: 390
      Abstract: Epidemiology and animal studies suggest that a paternal history of toxicant exposure contributes to the developmental origins of health and disease. Using a mouse model, our laboratory previously reported that a paternal history of in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased his offspring’s risk of developing necrotizing enterocolitis (NEC). Additionally, our group and others have found that formula supplementation also increases the risk of NEC in both humans and mice. Our murine studies revealed that intervening with a paternal fish oil diet preconception eliminated the TCDD-associated outcomes that are risk factors for NEC (e.g., intrauterine growth restriction, delayed postnatal growth, and preterm birth). However, the efficacy of a paternal fish oil diet in eliminating the risk of disease development in his offspring was not investigated. Herein, reproductive-age male mice exposed to TCDD in utero were weaned to a standard or fish oil diet for one full cycle of spermatogenesis, then mated to age-matched unexposed females. Their offspring were randomized to a strict maternal milk diet or a supplemental formula diet from postnatal days 7–10. Offspring colon contents and intestines were collected to determine the onset of gut dysbiosis and NEC. We found that a paternal fish oil diet preconception reduced his offspring’s risk of toxicant-driven NEC, which was associated with a decrease in the relative abundance of the Firmicutes phylum, but an increase in the relative abundance of the Negativicutes class.
      Citation: Marine Drugs
      PubDate: 2022-06-13
      DOI: 10.3390/md20060390
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 391: Anti-Inflammatory Effect of Sulfated
           Polysaccharides Isolated from Codium fragile In Vitro in RAW 264.7
           Macrophages and In Vivo in Zebrafish

    • Authors: Lei Wang, Jun-Geon Je, Caoxing Huang, Jae-Young Oh, Xiaoting Fu, Kaiqiang Wang, Ginnae Ahn, Jiachao Xu, Xin Gao, You-Jin Jeon
      First page: 391
      Abstract: In this study, the anti-inflammatory activity of sulfated polysaccharides isolated from the green seaweed Codium fragile (CFCE-PS) was investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and zebrafish. The results demonstrated that CFCE-PS significantly increased the viability of LPS-induced RAW 264.7 cells in a concentration-dependent manner. CFCE-PS remarkably and concentration-dependently reduced the levels of inflammatory molecules including prostaglandin E2, nitric oxide (NO), interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6 in LPS-stimulated RAW 264.7 cells. In addition, in vivo test results indicated that CFCE-PS effectively reduced reactive oxygen species, cell death, and NO levels in LPS-stimulated zebrafish. Thus, these results indicate that CFCE-PS possesses in vitro and in vivo anti-inflammatory activities and suggest it is a potential ingredient in the functional food and pharmaceutical industries.
      Citation: Marine Drugs
      PubDate: 2022-06-13
      DOI: 10.3390/md20060391
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 392: Antitumor Properties of Epitope-Specific
           Engineered Vaccine in Murine Model of Melanoma

    • Authors: Emiliya Stoyanova, Nikolina Mihaylova, Nikola Ralchev, Petya Ganova, Silviya Bradyanova, Iliyan Manoylov, Yuliana Raynova, Krassimira Idakieva, Andrey Tchorbanov
      First page: 392
      Abstract: Finding new effective compounds of natural origin for composing anti-tumor vaccines is one of the main goals of antitumor research. Promising anti-cancer agents are the gastropodan hemocyanins–multimeric copper-containing glycoproteins used so far for therapy of different tumors. The properties of hemocyanins isolated from the marine snail Rapana thomasiana (RtH) and the terrestrial snail Helix aspersa (HaH) upon their use as carrier-proteins in conjugated vaccines, containing ganglioside mimotope GD3P4 peptide, were studied in the developed murine melanoma model. Murine melanoma cell line B16F10 was used for solid tumor establishment in C57BL/6 mice using various schemes of therapy. Protein engineering, flow cytometry, and cytotoxicity assays were also performed. The administration of the protein-engineered vaccines RtH-GD3P4 or HaH-GD3P4 under the three different regimens of therapy in the B16F10 murine melanoma model suppressed tumor growth, decreased tumor incidence, and prolonged the survival of treated animals. The immunization of experimental mice induced an infiltration of immunocompetent cells into the tumors and generated cytotoxic tumor-specific T cells in the spleen. The treatment also generates significantly higher levels of tumor-infiltrated M1 macrophages, compared to untreated tumor-bearing control mice. This study demonstrated a promising approach for cancer therapy having potential applications for cancer vaccine research.
      Citation: Marine Drugs
      PubDate: 2022-06-14
      DOI: 10.3390/md20060392
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 393: Secondary Metabolites and Biosynthetic
           Gene Clusters Analysis of Deep-Sea Hydrothermal Vent-Derived Streptomyces
           sp. SCSIO ZS0520

    • Authors: Huaran Zhang, Yingying Chen, Yanqing Li, Yongxiang Song, Junying Ma, Jianhua Ju
      First page: 393
      Abstract: Streptomyces sp. SCSIO ZS0520 is a deep-sea hydrothermal vent-derived actinomycete. Our previous metabolism investigation showed that Streptomyces sp. SCSIO ZS0520 is a producer of cytotoxic actinopyrones. Here, another four types of secondary metabolites were identified, including six salinomycin isomers (2–7), the macrolide elaiophylin (8), the triterpene N-acetyl-aminobacteriohopanetriol (9), and the pyrone minipyrone (10). Among them, compounds 2–6 and 10 are new compounds. To understand the biosynthetic pathway of these compounds, a bioinformatic analysis of the whole genome was carried out, which identified 34 secondary metabolite biosynthetic gene clusters. Next, the biosynthetic pathways responsive to four types of products were deduced on the basis of gene function predictions and structure information. Taken together, these findings prove the metabolite potential of ZS0520 and lay the foundations to solve the remaining biosynthetic issues in four types of marine natural products.
      Citation: Marine Drugs
      PubDate: 2022-06-14
      DOI: 10.3390/md20060393
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 394: Youssoufenes A2 and A3, Antibiotic
           Dimeric Cinnamoyl Lipids from the ΔdtlA Mutant of a Marine-Derived
           Streptomyces Strain

    • Authors: Jing Liu, Huayue Li, Zengzhi Liu, Tong Li, Fei Xiao, Wenli Li
      First page: 394
      Abstract: Two new dimeric cinnamoyl lipids (CL) featuring with an unusual dearomatic carbon-bridge, named youssoufenes A2 (1) and A3 (2), were isolated from the ΔdtlA mutant strain of marine-derived Streptomyces youssoufiensis OUC6819. Structures of the isolated compounds were elucidated based on extensive MS and NMR spectroscopic analyses, and their absolute configurations were determined by combination of the long-range NOE-based 1H-1H distance measurements and ECD calculations. Compounds 1 and 2 exhibited moderate growth inhibition against multi-drug-resistant Enterococcus faecalis CCARM 5172 with an MIC value of 22.2 μM.
      Citation: Marine Drugs
      PubDate: 2022-06-15
      DOI: 10.3390/md20060394
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 395: Fast and Efficient Separation of Eleven
           Mycosporine-like Amino Acids by UHPLC-DAD and Their Quantification in
           Diverse Red Algae

    • Authors: Michael Zwerger, Markus Ganzera
      First page: 395
      Abstract: Due to their hostile habitats, characterized by a high exposure to UV-A and UV-B radiation, red algae are known to synthesize unique secondary metabolites: mycosporine-like amino acids (MAAs). These small molecules possess an extremely high UV absorption capacity and therefore mainly act as photoprotective agents. In this study, the first ultrahigh-performance liquid chromatography (UHPLC) method with diode-array detection (DAD) was developed for the determination of eleven MAAs in various algal species. All of the analytes could be separated in under 8 min on a Phenomenex Luna Omega C18 1.6 µm column. The mobile phase comprised water with 0.25% formic acid and 20 mM ammonium formate (A) and acetonitrile (B). Elution was carried out in gradient mode. Method validation following ICH guidelines confirmed excellent linearity (R2 ≥ 0.9998), selectivity, precision and accuracy (from 97.41 to 103.38%) for all analytes. The assay’s LOD was always 0.01 µg/mL; its LOQ was not higher than 0.04 µg/mL. Practical applicability was assured by analyzing several algae (e.g., Gracilaria chilensis, Pyropia plicata) using the developed method, and results indicated a high variation in MAA profiles as well as content. Whilst some MAAs were only found in specific samples, shinorine, which was always present, occurred in concentrations from 0.05 to 4.14 mg/g of dried biomass. As UHPLC-MS was also feasible, this method showed high flexibility concerning the detection mode, surpassing established procedures for MAA analysis not only concerning separation efficiency and analysis time.
      Citation: Marine Drugs
      PubDate: 2022-06-15
      DOI: 10.3390/md20060395
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 396: Applications of Chitosan in Surgical and
           Post-Surgical Materials

    • Authors: Fernando Notario-Pérez, Araceli Martín-Illana, Raúl Cazorla-Luna, Roberto Ruiz-Caro, María Dolores Veiga
      First page: 396
      Abstract: The continuous advances in surgical procedures require continuous research regarding materials with surgical applications. Biopolymers are widely studied since they usually provide a biocompatible, biodegradable, and non-toxic material. Among them, chitosan is a promising material for the development of formulations and devices with surgical applications due to its intrinsic bacteriostatic, fungistatic, hemostatic, and analgesic properties. A wide range of products has been manufactured with this polymer, including scaffolds, sponges, hydrogels, meshes, membranes, sutures, fibers, and nanoparticles. The growing interest of researchers in the use of chitosan-based materials for tissue regeneration is obvious due to extensive research in the application of chitosan for the regeneration of bone, nervous tissue, cartilage, and soft tissues. Chitosan can serve as a substance for the administration of cell-growth promoters, as well as a support for cellular growth. Another interesting application of chitosan is hemostasis control, with remarkable results in studies comparing the use of chitosan-based dressings with traditional cotton gauzes. In addition, chitosan-based or chitosan-coated surgical materials provide the formulation with antimicrobial activity that has been highly appreciated not only in dressings but also for surgical sutures or meshes.
      Citation: Marine Drugs
      PubDate: 2022-06-15
      DOI: 10.3390/md20060396
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 397: Marine Cyclic Peptides: Antimicrobial
           Activity and Synthetic Strategies

    • Authors: Ricardo Ribeiro, Eugénia Pinto, Carla Fernandes, Emília Sousa
      First page: 397
      Abstract: Oceans are a rich source of structurally unique bioactive compounds from the perspective of potential therapeutic agents. Marine peptides are a particularly interesting group of secondary metabolites because of their chemistry and wide range of biological activities. Among them, cyclic peptides exhibit a broad spectrum of antimicrobial activities, including against bacteria, protozoa, fungi, and viruses. Moreover, there are several examples of marine cyclic peptides revealing interesting antimicrobial activities against numerous drug-resistant bacteria and fungi, making these compounds a very promising resource in the search for novel antimicrobial agents to revert multidrug-resistance. This review summarizes 174 marine cyclic peptides with antibacterial, antifungal, antiparasitic, or antiviral properties. These natural products were categorized according to their sources—sponges, mollusks, crustaceans, crabs, marine bacteria, and fungi—and chemical structure—cyclic peptides and depsipeptides. The antimicrobial activities, including against drug-resistant microorganisms, unusual structural characteristics, and hits more advanced in (pre)clinical studies, are highlighted. Nocathiacins I–III (91–93), unnarmicins A (114) and C (115), sclerotides A (160) and B (161), and plitidepsin (174) can be highlighted considering not only their high antimicrobial potency in vitro, but also for their promising in vivo results. Marine cyclic peptides are also interesting models for molecular modifications and/or total synthesis to obtain more potent compounds, with improved properties and in higher quantity. Solid-phase Fmoc- and Boc-protection chemistry is the major synthetic strategy to obtain marine cyclic peptides with antimicrobial properties, and key examples are presented guiding microbiologist and medicinal chemists to the discovery of new antimicrobial drug candidates from marine sources.
      Citation: Marine Drugs
      PubDate: 2022-06-15
      DOI: 10.3390/md20060397
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 398: Targeted Large-Scale Genome Mining and
           Candidate Prioritization for Natural Product Discovery

    • Authors: Jessie James Limlingan Malit, Hiu Yu Cherie Leung, Pei-Yuan Qian
      First page: 398
      Abstract: Large-scale genome-mining analyses have identified an enormous number of cryptic biosynthetic gene clusters (BGCs) as a great source of novel bioactive natural products. Given the sheer number of natural product (NP) candidates, effective strategies and computational methods are keys to choosing appropriate BGCs for further NP characterization and production. This review discusses genomics-based approaches for prioritizing candidate BGCs extracted from large-scale genomic data, by highlighting studies that have successfully produced compounds with high chemical novelty, novel biosynthesis pathway, and potent bioactivities. We group these studies based on their BGC-prioritization logics: detecting presence of resistance genes, use of phylogenomics analysis as a guide, and targeting for specific chemical structures. We also briefly comment on the different bioinformatics tools used in the field and examine practical considerations when employing a large-scale genome mining study.
      Citation: Marine Drugs
      PubDate: 2022-06-16
      DOI: 10.3390/md20060398
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 399: In Silico Virtual Screening of Marine
           Aldehyde Derivatives from Seaweeds against SARS-CoV-2

    • Authors: Nalae Kang, Seong-Yeong Heo, Seon-Heui Cha, Ginnae Ahn, Soo-Jin Heo
      First page: 399
      Abstract: Coronavirus disease 2019, caused by the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing global pandemic that poses an unprecedented threat to the global economy and human health. Several potent inhibitors targeting SARS-CoV-2 have been published; however, most of them have failed in clinical trials. This study aimed to assess the therapeutic compounds among aldehyde derivatives from seaweeds as potential SARS-CoV-2 inhibitors using a computer simulation protocol. The absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox) properties of the compounds were analyzed using a machine learning algorithm, and the docking simulation of these compounds to the 3C-like protease (Protein Data Bank (PDB) ID: 6LU7) was analyzed using a molecular docking protocol based on the CHARMm algorithm. These compounds exhibited good drug-like properties following the Lipinski and Veber rules. Among the marine aldehyde derivatives, 4-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, and 5-bromoprotocatechualdehyde were predicted to have good absorption and solubility levels and non-hepatotoxicity in the ADME/Tox prediction. 3-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde were predicted to be non-toxic in TOPKAT prediction. In addition, 3,4-dihydroxybenzaldehyde was predicted to exhibit interactions with the 3C-like protease, with binding energies of −71.9725 kcal/mol. The computational analyses indicated that 3,4-dihydroxybenzaldehyde could be regarded as potential a SARS-CoV-2 inhibitor.
      Citation: Marine Drugs
      PubDate: 2022-06-16
      DOI: 10.3390/md20060399
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 400: Taeanamides A and B, Nonribosomal
           Lipo-Decapeptides Isolated from an Intertidal-Mudflat-Derived Streptomyces

    • Authors: Jinsheng Cui, Eunji Kim, Dong Hyun Moon, Tae Ho Kim, Ilnam Kang, Yeonjung Lim, Daniel Shin, Sunghoon Hwang, Young Eun Du, Myoung Chong Song, Munhyung Bae, Jang-Cheon Cho, Jichan Jang, Sang Kook Lee, Yeo Joon Yoon, Dong-Chan Oh
      First page: 400
      Abstract: Two new lipo-decapeptides, namely taeanamides A and B (1 and 2), were discovered from the Gram-positive bacterium Streptomyces sp. AMD43, which was isolated from a mudflat sample from Anmyeondo, Korea. The exact molecular masses of 1 and 2 were revealed by high-resolution mass spectrometry, and the planar structures of 1 and 2 were elucidated using NMR spectroscopy. The absolute configurations of 1 and 2 were determined using a combined analysis of 1H-1H coupling constants and ROESY correlations, the advanced Marfey’s method, and bioinformatics. The putative nonribosomal peptide synthetase pathway for the taeanamides was identified by analyzing the full genome sequence data of Streptomyces sp. AMD43. We also found that taeanamide A exhibited mild anti-tuberculosis bioactivity, whereas taeanamide B showed significant bioactivity against several cancer cell lines.
      Citation: Marine Drugs
      PubDate: 2022-06-16
      DOI: 10.3390/md20060400
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 401: Preparation of Ion2+-COS/SA
           Multifunctional Gel Films for Skin Wound Healing by an In Situ Spray

    • Authors: Liqi Chen, Tingting Guo, Chao Shi, Kun Zhang, Shenghao Cui, Di Zhao, Faming Yang, Jingdi Chen
      First page: 401
      Abstract: The rapid preparation of safe and efficient wound dressings that meet the needs of the entire repair process remains a major challenge for effective therapeutic wound healing. Natural, sprayable Ion2+-COS/SA multifunctional dual-network gel films created by the in situ coordination of chitooligosaccharide (COS), metal ions and sodium alginate (SA) using casting and an in-situ spray method were synthesized. The gel films exhibited excellent physicochemical properties such as swelling, porosity and plasticity at a COS mass fraction of 3%. Furthermore, at this mass fraction, the addition of bimetallic ions led to the display of multifunctional properties, including significant antioxidant, antibacterial and cytocompatibility properties. In addition, experiments in a total skin defect model showed that this multifunctional gel film accelerates wound healing and promotes skin regeneration. These results suggest that the sprayable Ion2+-COS/SA multifunctional pro-healing gel film may be a promising candidate for the clinical treatment of allodermic wounds.
      Citation: Marine Drugs
      PubDate: 2022-06-18
      DOI: 10.3390/md20060401
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 402: Injectable Thermosensitive
           Chitosan-Collagen Hydrogel as A Delivery System for Marine Polysaccharide

    • Authors: Julia Ohmes, Lena Marie Saure, Fabian Schütt, Marie Trenkel, Andreas Seekamp, Regina Scherließ, Rainer Adelung, Sabine Fuchs
      First page: 402
      Abstract: Fucoidans, sulfated polysaccharides from brown algae, possess multiple bioactivities in regard to osteogenesis, angiogenesis, and inflammation, all representing key molecular processes for successful bone regeneration. To utilize fucoidans in regenerative medicine, a delivery system is needed which temporarily immobilizes the polysaccharide at the injured site. Hydrogels have become increasingly interesting biomaterials for the support of bone regeneration. Their structural resemblance with the extracellular matrix, their flexible shape, and capacity to deliver bioactive compounds or stem cells into the affected tissue make them promising materials for the support of healing processes. Especially injectable hydrogels stand out due to their minimal invasive application. In the current study, we developed an injectable thermosensitive hydrogel for the delivery of fucoidan based on chitosan, collagen, and β-glycerophosphate (β-GP). Physicochemical parameters such as gelation time, gelation temperature, swelling capacity, pH, and internal microstructure were studied. Further, human bone-derived mesenchymal stem cells (MSC) and human outgrowth endothelial cells (OEC) were cultured on top (2D) or inside the hydrogels (3D) to assess the biocompatibility. We found that the sol-gel transition occurred after approximately 1 min at 37 °C. Fucoidan integration into the hydrogel had no or only a minor impact on the mentioned physicochemical parameters compared to hydrogels which did not contain fucoidan. Release assays showed that 60% and 80% of the fucoidan was released from the hydrogel after two and six days, respectively. The hydrogel was biocompatible with MSC and OEC with a limitation for OEC encapsulation. This study demonstrates the potential of thermosensitive chitosan-collagen hydrogels as a delivery system for fucoidan and MSC for the use in regenerative medicine.
      Citation: Marine Drugs
      PubDate: 2022-06-18
      DOI: 10.3390/md20060402
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 403: Algal Phlorotannins as Novel
           Antibacterial Agents with Reference to the Antioxidant Modulation: Current
           Advances and Future Directions

    • Authors: Biswajita Pradhan, Rabindra Nayak, Prajna Paramita Bhuyan, Srimanta Patra, Chhandashree Behera, Sthitaprajna Sahoo, Jang-Seu Ki, Alessandra Quarta, Andrea Ragusa, Mrutyunjay Jena
      First page: 403
      Abstract: The increasing drug resistance of infectious microorganisms is considered a primary concern of global health care. The screening and identification of natural compounds with antibacterial properties have gained immense popularity in recent times. It has previously been shown that several bioactive compounds derived from marine algae exhibit antibacterial activity. Similarly, polyphenolic compounds are generally known to possess promising antibacterial capacity, among other capacities. Phlorotannins (PTs), an important group of algae-derived polyphenolic compounds, have been considered potent antibacterial agents both as single drug entities and in combination with commercially available antibacterial drugs. In this context, this article reviews the antibacterial properties of polyphenols in brown algae, with particular reference to PTs. Cell death through various molecular modes of action and the specific inhibition of biofilm formation by PTs were the key discussion of this review. The synergy between drugs was also discussed in light of the potential use of PTs as adjuvants in the pharmacological antibacterial treatment.
      Citation: Marine Drugs
      PubDate: 2022-06-18
      DOI: 10.3390/md20060403
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 404: Deep-Sea Natural Products from Extreme
           Environments: Cold Seeps and Hydrothermal Vents

    • Authors: Mengjing Cong, Xiaoyan Pang, Kai Zhao, Yue Song, Yonghong Liu, Junfeng Wang
      First page: 404
      Abstract: The deep sea has been proven to be a great treasure for structurally unique and biologically active natural products in the last two decades. Cold seeps and hydrothermal vents, as typical representatives of deep-sea extreme environments, have attracted more and more attention. This review mainly summarizes the natural products of marine animals, marine fungi, and marine bacteria derived from deep-sea cold seeps and hydrothermal vents as well as their biological activities. In general, there were 182 compounds reported, citing 132 references and covering the literature from the first report in 1984 up to March 2022. The sources of the compounds are represented by the genera Aspergillus sp., Penicillium sp., Streptomyces sp., and so on. It is worth mentioning that 90 of the 182 compounds are new and that almost 60% of the reported structures exhibited diverse bioactivities, which became attractive targets for relevant organic synthetic and biosynthetic studies.
      Citation: Marine Drugs
      PubDate: 2022-06-19
      DOI: 10.3390/md20060404
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 405: Progress in Isoindolone Alkaloid
           Derivatives from Marine Microorganism: Pharmacology, Preparation, and

    • Authors: Sijin Hang, Hui Chen, Wenhui Wu, Shiyi Wang, Yiwen Fang, Ruilong Sheng, Qidong Tu, Ruihua Guo
      First page: 405
      Abstract: Compound 1 (SMTP-7, also FGFC1), an isoindolone alkaloid from marine fungi Starchbotrys longispora FG216 and fungi Stachybotrys microspora IFO 30018, possessed diverse bioactivities such as thrombolysis, anti-inflammatory and anti-oxidative properties, and so on. It may be widely used for the treatment of various diseases, including cerebral infarction, stroke, ischemia/reperfusion damage, acute kidney injury, etc. Especially in cerebral infarction, compound 1 could reduce hemorrhagic transformation along with thrombolytic therapy, as the traditional therapies are accompanied with bleeding risks. In the latest studies, compound 1 selectively inhibited the growth of NSCLC cells with EGFR mutation, thus demonstrating its excellent anti-cancer activity. Herein, we summarized pharmacological activities, preparation of staplabin congeners—especially compound 1—and the mechanism of compound 1, with potential therapeutic applications.
      Citation: Marine Drugs
      PubDate: 2022-06-20
      DOI: 10.3390/md20060405
      Issue No: Vol. 20, No. 6 (2022)
  • Marine Drugs, Vol. 20, Pages 308: Anti-Photoaging Effect of Hydrolysates
           from Pacific Whiting Skin via MAPK/AP-1, NF-κB, TGF-β/Smad, and
           Nrf-2/HO-1 Signaling Pathway in UVB-Induced Human Dermal Fibroblasts

    • Authors: Seok Hee Han, Elaine Ballinger, Se-Young Choung, Jung Yeon Kwon
      First page: 308
      Abstract: Chronic exposure to ultraviolet (UV) light promotes the breakdown of collagen in the skin and disrupts the extracellular matrix (ECM) structure, leading to skin wrinkling. Pacific whiting (Merluccius productus) is a fish abundant on the Pacific coast. In the current study, we investigated the anti-wrinkle effect of hydrolysate from Pacific whiting skin gelatin (PWG) in UVB-irradiated human dermal fibroblasts and the molecular mechanisms involved. PWG effectively restored type 1 procollagen synthesis reduced by UVB-irradiation. Also, we found that PWG inhibited collagen degradation by inhibiting MMP1 expression. Furthermore, PWG decreased cytokines TNF-α, IL-6, and IL-1β associated with inflammatory responses and increased antioxidant enzymes, HO-1, SOD, GPx, CAT, and GSH content, a defense system against oxidative stress. In terms of molecular mechanisms, PWG increased collagen synthesis through activating the transforming growth factor β (TGF-β)/Smad pathway and decreased collagen degradation through inhibiting the mitogen-activated protein kinases/activator protein 1 (MAPK/AP-1) pathway. It also suppressed the inflammatory response through suppressing the nuclear factor-κB (NF-κB) pathway and increased antioxidant enzyme activity through activating the nuclear factor erythroid 2/heme oxygenase 1 (Nrf-2/HO-1) pathway. These multi-target mechanisms suggest that PWG may serve as an effective anti-photoaging material.
      Citation: Marine Drugs
      PubDate: 2022-04-30
      DOI: 10.3390/md20050308
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 309: Valorization of Side Stream Products
           from Sea Cage Fattened Bluefin Tuna (Thunnus thynnus): Production and In
           Vitro Bioactivity Evaluation of Enriched ω-3 Polyunsaturated Fatty

    • Authors: Concetta Maria Messina, Rosaria Arena, Simona Manuguerra, Laura La La Barbera, Eleonora Curcuraci, Giuseppe Renda, Andrea Santulli
      First page: 309
      Abstract: The valorization of side streams from fishery and aquaculture value-chains is a valuable solution to address one of the challenges of the circular economy: turning wastes into profit. Side streams produced after filleting of sea cage fattened bluefin tuna (Thunnus thynnus) were analyzed for proximate composition and fatty acid profile to evaluate the possibility of producing tuna oil (TO) as a valuable source of ω-3 polyunsaturated fatty acids (PUFA) and testing its bioactivity in vitro. Ethyl esters of total fatty acids (TFA), obtained from TO, were pre-enriched by urea complexation (PUFA-Ue) and then enriched by short path distillation (SPD) up to almost 85% of the PUFA fraction (PUFA-SPe). The bioactivity of TFA, PUFA-SPe, and ethyl esters of depleted PUFA (PUFA-SPd) were tested in vitro, through analysis of lipid metabolism genes, in gilthead sea bream (Sparus aurata) fibroblast cell line (SAF-1) exposed to oils. TFA and PUFA-SPd upregulated transcription factors (pparβ and pparγ) and lipid metabolism-related genes (D6D, fas, fabp, fatp1, and cd36), indicating the promotion of adipogenesis. PUFA-SPe treated cells were similar to control. PUFA-SPe extracted from farmed bluefin tuna side streams could be utilized in fish feed formulations to prevent excessive fat deposition, contributing to improving both the sustainability of aquaculture and the quality of its products.
      Citation: Marine Drugs
      PubDate: 2022-04-30
      DOI: 10.3390/md20050309
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 310: Biodegradation and Prospect of
           Polysaccharide from Crustaceans

    • Authors: Shuting Qiu, Shipeng Zhou, Yue Tan, Jiayao Feng, Yan Bai, Jincan He, Hua Cao, Qishi Che, Jiao Guo, Zhengquan Su
      First page: 310
      Abstract: Marine crustacean waste has not been fully utilized and is a rich source of chitin. Enzymatic degradation has attracted the wide attention of researchers due to its unique biocatalytic ability to protect the environment. Chitosan (CTS) and its derivative chitosan oligosaccharides (COSs) with various biological activities can be obtained by the enzymatic degradation of chitin. Many studies have shown that chitosan and its derivatives, chitosan oligosaccharides (COSs), have beneficial properties, including lipid-lowering, anti-inflammatory and antitumor activities, and have important application value in the medical treatment field, the food industry and agriculture. In this review, we describe the classification, biochemical characteristics and catalytic mechanisms of the major degrading enzymes: chitinases, chitin deacetylases (CDAs) and chitosanases. We also introduced the technology for enzymatic design and modification and proposed the current problems and development trends of enzymatic degradation of chitin polysaccharides. The discussion on the characteristics and catalytic mechanism of chitosan-degrading enzymes will help to develop new types of hydrolases by various biotechnology methods and promote their application in chitosan.
      Citation: Marine Drugs
      PubDate: 2022-05-02
      DOI: 10.3390/md20050310
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 311: Chasing Chances in a Changing Sea

    • Authors: Ernesto Mollo
      First page: 311
      Abstract: Bioactive marine natural products (BMNPs) of interest for applications as drugs, antimicrobials, cosmetics, nutraceuticals, or antifoulants, are often present in traces in producer organisms and often occur in threatened or endangered species, or in organisms playing key ecological roles [...]
      Citation: Marine Drugs
      PubDate: 2022-05-03
      DOI: 10.3390/md20050311
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 312: Monkfish Peptides Mitigate High Fat
           Diet-Induced Hepatic Steatosis in Mice

    • Authors: Jiena Ye, Xiaoxiao Tian, Qiongfen Wang, Jiawen Zheng, Yanzhuo Yang, Baogui Xu, Shuai Zhang, Falei Yuan, Zuisu Yang
      First page: 312
      Abstract: Non-alcoholic fatty liver disease (NAFLD) is a hepatic metabolic syndrome usually accompanied by fatty degeneration and functional impairment. The aim of the study was to determine whether monkfish peptides (LPs) could ameliorate high-fat diet (HFD)-induced NAFLD and its underlying mechanisms. NAFLD was induced in mice by giving them an HFD for eight weeks, after which LPs were administered in various dosages. In comparison to the HFD control group: body weight in the LP-treated groups decreased by 23–28%; triacylglycerol levels in the blood decreased by 16–35%; and low-density lipoproteins levels in the blood decreased by 23–51%. Additionally, we found that LPs elevated the activity of hepatic antioxidant enzymes and reduced the inflammatory reactions within fatty liver tissue. Investigating the effect on metabolic pathways, we found that in LP-treated mice: the levels of phospho-AMP-activated protein kinase (p-AMPK), and phospho-acetyl CoA carboxylase (p-ACC) in the AMP-activated protein kinase (AMPK) pathway were up-regulated and the levels of downstream sterol regulatory element-binding transcription factor 1 (SREBP-1) were down-regulated; lipid oxidation increased and free fatty acid (FFA) accumulation decreased (revealed by the increased carnitine palmitoyltransferase-1 (CPT-1) and the decreased fatty acid synthase (FASN) expression, respectively); the nuclear factor erythroid-2-related factor 2 (Nrf2) antioxidant pathway was activated; and the levels of heme oxygenase-1 (HO-1) and nicotinamide quinone oxidoreductase 1 (NQO1) were increased. Overall, all these findings demonstrated that LPs can improve the antioxidant capacity of liver to alleviate NAFLD progression mainly through modulating the AMPK and Nrf2 pathways, and thus it could be considered as an effective candidate in the treatment of human NAFLD.
      Citation: Marine Drugs
      PubDate: 2022-05-05
      DOI: 10.3390/md20050312
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 313: Balenine, Imidazole Dipeptide Promotes
           Skeletal Muscle Regeneration by Regulating Phagocytosis Properties of
           Immune Cells

    • Authors: Min Yang, Luchuanyang Sun, Yasunosuke Kawabata, Fumihito Murayama, Takahiro Maegawa, Takeshi Nikawa, Katsuya Hirasaka
      First page: 313
      Abstract: Balenine is one of the endogenous imidazole dipeptides derived from marine products. It is composed of beta-alanine and 3-methyl-L-histidine, which exist mainly in the muscles of marine organisms. The physiological functions of dietary balenine are not well-known. In this study, we investigated whether the supplementation of dietary balenine was associated with muscle function in a cardiotoxin-indued muscle degeneration/regeneration model. Through morphological observation, we found that the supplementation of balenine-enriched extract promoted the regeneration stage. In addition, the expression of regeneration-related myogenic marker genes, such as paired box protein 7, MyoD1, myogenin, and Myh3, in a group of mice fed a balenine-enriched extract diet was higher than that in a group fed a normal diet. Moreover, the supplementation of balenine-enriched extract promoted the expression of anti-inflammatory cytokines as well as pro-inflammatory cytokines at the degeneration stage. Interestingly, phagocytic activity in the balenine group was significantly higher than that in the control group in vitro. These results suggest that balenine may promote the progress of muscle regeneration by increasing the phagocytic activity of macrophages.
      Citation: Marine Drugs
      PubDate: 2022-05-05
      DOI: 10.3390/md20050313
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 314: Marine Biopolymers as Bioactive
           Functional Ingredients of Electrospun Nanofibrous Scaffolds for Biomedical

    • Authors: Konstantina Iliou, Stefanos Kikionis, Efstathia Ioannou, Vassilios Roussis
      First page: 314
      Abstract: Marine biopolymers, abundantly present in seaweeds and marine animals, feature diverse structures and functionalities, and possess a wide range of beneficial biological activities. Characterized by high biocompatibility and biodegradability, as well as unique physicochemical properties, marine biopolymers are attracting a constantly increasing interest for the development of advanced systems for applications in the biomedical field. The development of electrospinning offers an innovative technological platform for the production of nonwoven nanofibrous scaffolds with increased surface area, high encapsulation efficacy, intrinsic interconnectivity, and structural analogy to the natural extracellular matrix. Marine biopolymer-based electrospun nanofibrous scaffolds with multifunctional characteristics and tunable mechanical properties now attract significant attention for biomedical applications, such as tissue engineering, drug delivery, and wound healing. The present review, covering the literature up to the end of 2021, highlights the advancements in the development of marine biopolymer-based electrospun nanofibers for their utilization as cell proliferation scaffolds, bioadhesives, release modifiers, and wound dressings.
      Citation: Marine Drugs
      PubDate: 2022-05-05
      DOI: 10.3390/md20050314
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 315: BDDE-Inspired Chalcone Derivatives to
           Fight Bacterial and Fungal Infections

    • Authors: Ana Jesus, Fernando Durães, Nikoletta Szemerédi, Joana Freitas-Silva, Paulo Martins da Costa, Eugénia Pinto, Madalena Pinto, Gabriella Spengler, Emília Sousa, Honorina Cidade
      First page: 315
      Abstract: The growing number of infectious diseases around the world threatens the effective response of antibiotics, contributing to the increase in antibiotic resistance seen as a global health problem. Currently, one of the main challenges in antimicrobial drug discovery is the search for new compounds that not only exhibit antimicrobial activity, but can also potentiate the antimicrobial activity and revert antibiotics’ resistance, through the interference with several mechanisms, including the inhibition of efflux pumps (EPs) and biofilm formation. Inspired by macroalgae brominated bromophenol BDDE with antimicrobial activity, a series of 18 chalcone derivatives, including seven chalcones (9–15), six dihydrochalcones (16–18, and 22–24) and five diarylpropanes (19–21, and 25 and 26), was prepared and evaluated for its antimicrobial activity and potential to fight antibiotic resistance. Among them, chalcones 13 and 14 showed promising antifungal activity against the dermatophyte clinical strain of Trichophyton rubrum, and all compounds reversed the resistance to vancomycin in Enterococcus faecalis B3/101, with 9, 14, and 24 able to cause a four-fold decrease in the MIC of vancomycin against this strain. Compounds 17–24 displayed inhibition of EPs and the formation of biofilm by S. aureus 272123, suggesting that these compounds are inhibiting the EPs responsible for the extrusion of molecules involved in biofilm-related mechanisms. Interestingly, compounds 17–24 did not show cytotoxicity in mouse embryonic fibroblast cell lines (NIH/3T3). Overall, the results obtained suggest the potential of dihydrochalcones 16–18 and 22–24, and diarylpropanes 19–21, 25 and 26, as hits for bacterial EPs inhibition, as they are effective in the inhibition of EPs, but present other features that are important in this matter, such as the lack of antibacterial activity and cytotoxicity.
      Citation: Marine Drugs
      PubDate: 2022-05-08
      DOI: 10.3390/md20050315
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 316: Inhibition of Lipopolysaccharide-Induced
           Inflammatory Signaling by Soft Coral-Derived Prostaglandin A2 in RAW264.7

    • Authors: Osamu Ohno, Eika Mizuno, Junichiro Miyamoto, Tomoyuki Hoshina, Takuya Sano, Kenji Matsuno
      First page: 316
      Abstract: Lipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria and causes inflammatory diseases. We searched MeOH extracts of collected marine organisms for inhibitors of LPS-induced nitric oxide (NO) production in RAW264.7 cells and identified prostaglandin A2 (PGA2) as an active compound from the MeOH extract of the soft coral Lobophytum sp. PGA2 inhibited the production of NO and reduced the expression of inducible NO synthase (iNOS) in LPS-stimulated RAW264.7 cells. Although short preincubation with PGA2 did not inhibit LPS-induced degradation and resynthesis of IκBα, the suppressive effect of PGA2 was observed only after a prolonged incubation period prior to LPS treatment. In addition, PGA2-inhibited NO production was negated by the addition of the EP4 antagonist L161982. Thus, PGA2 was identified as an inhibitor of LPS-induced inflammatory signaling in RAW264.7 cells.
      Citation: Marine Drugs
      PubDate: 2022-05-09
      DOI: 10.3390/md20050316
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 317: Bioactive Peptides from Algae:
           Traditional and Novel Generation Strategies, Structure-Function
           Relationships, and Bioinformatics as Predictive Tools for Bioactivity

    • Authors: Jack O’Connor, Marco Garcia-Vaquero, Steve Meaney, Brijesh Kumar Tiwari
      First page: 317
      Abstract: Over the last decade, algae have been explored as alternative and sustainable protein sources for a balanced diet and more recently, as a potential source of algal-derived bioactive peptides with potential health benefits. This review will focus on the emerging processes for the generation and isolation of bioactive peptides or cryptides from algae, including: (1) pre-treatments of algae for the extraction of protein by physical and biochemical methods; and (2) methods for the generation of bioactive including enzymatic hydrolysis and other emerging methods. To date, the main biological properties of the peptides identified from algae, including anti-hypertensive, antioxidant and anti-proliferative/cytotoxic effects (for this review, anti-proliferative/cytotoxic will be referred to by the term anti-cancer), assayed in vitro and/or in vivo, will also be summarized emphasizing the structure–function relationship and mechanism of action of these peptides. Moreover, the use of in silico methods, such as quantitative structural activity relationships (QSAR) and molecular docking for the identification of specific peptides of bioactive interest from hydrolysates will be described in detail together with the main challenges and opportunities to exploit algae as a source of bioactive peptides.
      Citation: Marine Drugs
      PubDate: 2022-05-10
      DOI: 10.3390/md20050317
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 318: In Vivo Nutritional Assessment of the
           Microalga Nannochloropsis gaditana and Evaluation of the Antioxidant and
           Antiproliferative Capacity of Its Functional Extracts

    • Authors: Rosario Martínez, Alejandro García-Beltrán, Garyfallia Kapravelou, Cristina Mesas, Laura Cabeza, Gloria Perazzoli, Palmira Guarnizo, Alberto Rodríguez-López, Roberto Andrés Vallejo, Milagros Galisteo, Pilar Aranda, Jose Prados, María López-Jurado, Consolación Melguizo, Jesus M. Porres
      First page: 318
      Abstract: Nannochloropsis gaditana is a microalga with interesting nutritional and functional value due to its high content of protein, polyunsaturated fatty acids, and bioactive compounds. However, the hardness of its cell wall prevents accessibility to these components. This work aimed to study the effect of a treatment to increase the fragility of the cell wall on the bioavailability of its nutrients and functional compounds. The antioxidant and antiproliferative capacity of functional extracts from treated and untreated N. gaditana was assessed, and the profile of bioactive compounds was characterized. Furthermore, to study the effect of treatment on its nutrient availability and functional capacity, an in vivo experiment was carried out using a rat experimental model and a 20% dietary inclusion level of microalgae. Functional extracts from treated N. gaditana exhibited higher antioxidant activity than the untreated control. Furthermore, the treated microalga induced hypoglycemic action, higher nitrogen digestibility, and increased hepatic antioxidant activity. In conclusion, N. gaditana has interesting hepatoprotective, antioxidant, and anti-inflammatory potential, thus proving itself an ideal functional food candidate, especially if the microalga is treated to increase the fragility of its cell wall before consumption.
      Citation: Marine Drugs
      PubDate: 2022-05-11
      DOI: 10.3390/md20050318
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 319: The Inhibitors of CDK4/6 from a Library
           of Marine Compound Database: A Pharmacophore, ADMET, Molecular Docking and
           Molecular Dynamics Study

    • Authors: Lianxiang Luo, Qu Wang, Yinglin Liao
      First page: 319
      Abstract: Background: CDK4/6 (Cyclin-dependent kinases 4/6) are the key promoters of cell cycle transition from G1 phase to S phase. Thus, selective inhibition of CDK4/6 is a promising cancer treatment. Methods: A total of 52,765 marine natural products were screened for CDK4/6. To screen out better natural compounds, pharmacophore models were first generated, then the absorption, distribution, metabolism, elimination, and toxicity (ADMET) were tested, followed by molecular docking. Finally, molecular dynamics simulation was carried out to verify the binding characteristics of the selected compounds. Results: Eighty-seven marine small molecules were screened based on the pharmacophore model. Then, compounds 41369 and 50843 were selected according to the ADMET and molecular docking score for further kinetic simulation evaluation. Finally, through molecular dynamics analysis, it was confirmed that compound 50843 maintained a stable conformation with the target protein, so it has the opportunity to become an inhibitor of CDK4/6. Conclusion: Through structure-based pharmacophore modeling, ADMET, the molecular docking method and molecular dynamics (MD) simulation, marine natural compound 50843 was proposed as a promising marine inhibitor of CDK4/6.
      Citation: Marine Drugs
      PubDate: 2022-05-12
      DOI: 10.3390/md20050319
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 320: Application of MS-Based Metabolomic
           Approaches in Analysis of Starfish and Sea Cucumber Bioactive Compounds

    • Authors: Roman S. Popov, Natalia V. Ivanchina, Pavel S. Dmitrenok
      First page: 320
      Abstract: Today, marine natural products are considered one of the main sources of compounds for drug development. Starfish and sea cucumbers are potential sources of natural products of pharmaceutical interest. Among their metabolites, polar steroids, triterpene glycosides, and polar lipids have attracted a great deal of attention; however, studying these compounds by conventional methods is challenging. The application of modern MS-based approaches can help to obtain valuable information about such compounds. This review provides an up-to-date overview of MS-based applications for starfish and sea cucumber bioactive compounds analysis. While describing most characteristic features of MS-based approaches in the context of starfish and sea cucumber metabolites, including sample preparation and MS analysis steps, the present paper mainly focuses on the application of MS-based metabolic profiling of polar steroid compounds, triterpene glycosides, and lipids. The application of MS in metabolomics studies is also outlined.
      Citation: Marine Drugs
      PubDate: 2022-05-12
      DOI: 10.3390/md20050320
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 321: Taxonomic and Bioactivity
           Characterizations of Mameliella alba Strain LZ-28 Isolated from Highly
           Toxic Marine Dinoflagellate Alexandrium catenella LZT09

    • Authors: Cheng-Zhe Ren, Hui-Min Gao, Jun Dai, Wen-Zhuo Zhu, Fei-Fei Xu, Yun Ye, Xiao-Ling Zhang, Qiao Yang
      First page: 321
      Abstract: Microalgae host varied microbial consortium harboring cross-kingdom interactions with fundamental ecological significance in aquatic ecosystems. Revealing the complex biofunctions of the cultivable bacteria of phycosphere microbiota is one vital basis for deeply understanding the mechanisms governing these dynamic associations. In this study, a new light-yellow pigmented bacterial strain LZ-28 was isolated from the highly-toxic and harmful algal bloom-forming dinoflagellate Alexandrium catenella LZT09. Collective phenotypic and genotypic profiles were obtained to confidently identify this strain as a new Mameliellaalba member. Comparative genomic analysis showed that strain LZ-28 shared highly similar functional features with other four marine algae-derived M. alba strains in spite of their distinctive isolation sources. Based on the bioactivity assaying, the mutual growth-promoting effects between bacterial strain LZ-28 and algal strain LZT09 were observed. After the culture conditions were optimized, strain LZ-28 demonstrated an extraordinary production ability for its bioflocculanting exopolysaccharides (EPS). Moreover, the portions of two monosaccharides glucose and fucose of the EPS were found to positively contribute to the bioflocculanting capacity. Therefore, the present study sheds light on the similar genomic features among the selected M. alba strains, and it also reveals the potential pharmaceutical, environmental and biotechnological implications of active EPS produced by this new Mameliella alba strain LZ-28 recovered from toxic bloom-forming marine dinoflagellate.
      Citation: Marine Drugs
      PubDate: 2022-05-12
      DOI: 10.3390/md20050321
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 322: Homo/Hetero-Dimers of Aromatic
           Bisabolane Sesquiterpenoids with Neuroprotective Activity from the Fungus
           Aspergillus versicolor A18 from South China Sea

    • Authors: Han-Zhuang Weng, Jun-Yu Zhu, Fang-Yu Yuan, Zhuo-Ya Tang, Xiao-Qing Tian, Ye Chen, Cheng-Qi Fan, Gui-Hua Tang, Sheng Yin
      First page: 322
      Abstract: Chromatographic fractionation of the EtOH extracts of the marine-derived fungus Aspergillus versicolor A18 has led to the isolation of 11 homo/hetero-dimers of aromatic bisabolane sesquiterpenoids including eight diphenyl ether-coupled aromatic bisabolanes (1a/1b and 5–10) and three homodimers (2–4), together with their monomers including three aromatic bisabolanes (11–13) and two diphenyl ethers (14 and 15). Their structures and absolute configurations were elucidated by extensive spectroscopic analysis including HRESIMS, 1D/2D NMR, calculated ECD, and the optical rotatory data. Among the four new compounds, (+/−)-asperbisabol A (1a/1b), asperbisabol B (2), and asperbisabol C (3), the enantiomers 1a and 1b represent an unprecedented skeleton of diphenyl ether-coupled aromatic bisabolane sesquiterpenoids with a spiroketal core moiety. The neuroprotective effects of selected compounds against sodium nitroprusside (SNP)-induced injury were evaluated in PC12 cells by the MTT assay. Five compounds (1a, 6, and 8–10) showed remarkable neuroprotective activities at 10 μM, being more active than the positive control edaravone.
      Citation: Marine Drugs
      PubDate: 2022-05-13
      DOI: 10.3390/md20050322
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 323: Effects of Formulation on the
           Palatability and Efficacy of In-Feed Praziquantel Medications for Marine
           Finfish Aquaculture

    • Authors: Edith K. Y. Tang, Gavin J. Partridge, Lindsey D. Woolley, Luke Pilmer, Lee Yong Lim
      First page: 323
      Abstract: Praziquantel (PZQ) provides an effective treatment against monogenean parasitic infestations in finfish. However, its use as an in-feed treatment is challenging due to palatability issues. In this study, five formulations of PZQ beads (1–4 mm) were developed using marine-based polymers, with allicin added as a flavouring agent. All formulations attained PZQ loading rates ≥74% w/w, and the beads were successfully incorporated into fish feed pellets at an active dietary inclusion level of 10 g/kg. When tested for palatability and digestibility in small yellowtail kingfish, the PZQ-loaded beads produced with alginate-chitosan, alginate-Cremophor® RH40, and agar as carriers resulted in high consumption rates of 99–100% with no digesta or evidence of beads in the gastrointestinal tract (GIT) of fish fed with diets containing either formulation. Two formulations produced using chitosan-based carriers resulted in lower consumption rates of 68–75%, with undigested and partly digested beads found in the fish GIT 3 h post feeding. The PZQ-loaded alginate-chitosan and agar beads also showed good palatability in large (≥2 kg) yellowtail kingfish infected with gill parasites and were efficacious in removing the parasites from the fish, achieving >90% reduction in mean abundance relative to control fish (p < 0.001). The two effective formulations were stable upon storage at ambient temperature for up to 18 months, showing residual drug content >90% compared with baseline levels. Overall, the palatability, efficacy and stability data collected from this study suggest that these two PZQ particulate formulations have potential applications as in-feed anti-parasitic medications for the yellowtail kingfish farming industry.
      Citation: Marine Drugs
      PubDate: 2022-05-13
      DOI: 10.3390/md20050323
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 324: The Impact of Natural Deep Eutectic
           Solvents and Extraction Method on the Co-Extraction of Trace Metals from
           Fucus vesiculosus

    • Authors: Alexander N. Shikov, Ekaterina D. Obluchinskaya, Elena V. Flisyuk, Inna I. Terninko, Yulia E. Generalova, Olga N. Pozharitskaya
      First page: 324
      Abstract: In recent years, natural deep eutectic solvents (NADES) have been widely investigated for the extraction of food and medicinal plants as well as seaweeds. However, the ability of NADES for trace elements co-extraction from natural sources is not well investigated. The aim of this study was to investigate the ability of common NADES for trace elements co-extraction from Fucus vesiculosus. All of the tested NADES did not recover As and Co (concentration <LOQ). Moreover, all of the tested NADES provided a low recovery (<9%) of Ba, Ca, Fe, Mg, Mn, Sr, and Zn. The method of extraction had not shown a statistically significant effect on the co-extraction of all elements (excluding Ba and Ca). In contrast, the water content in NADES was significantly affected on the recovery of Ba, Ca, Mg, Mn, Sr, and Zn. The recovery of Al and Cr was relatively high and considerably varied (from 1.5 to 59.9%). NADES comprising lactic acid:glucose:H2O (5:3:1) provided the lowest contents of all elements, and the highest extracted amounts were obtained employing water contents of 60–80%. The calculated daily intake of all the elements contained in NADES extracts were less than the daily dose risk estimators. The hazard quotients, hazard indexes, and carcinogenic risk calculated for all trace elements and their combination were considerably less than 1. This evidences no health risk, and carcinogenic risk after topical application of all studied NADES. For the first time, the results of the current study demonstrated that NADES extracts of F. vesiculosus contain a lower amount of trace metals and are safer than the extracts obtained with water and 70% acetone. This indicates a significant advantage for NADES compared with the other solvents.
      Citation: Marine Drugs
      PubDate: 2022-05-13
      DOI: 10.3390/md20050324
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 325: Novel Antioxidant Collagen Peptides of
           Siberian Sturgeon (Acipenserbaerii) Cartilages: The Preparation,
           Characterization, and Cytoprotection of H2O2-Damaged Human Umbilical Vein
           Endothelial Cells (HUVECs)

    • Authors: Yan Sheng, Yi-Ting Qiu, Yu-Mei Wang, Chang-Feng Chi, Bin Wang
      First page: 325
      Abstract: For making full use of aquatic by-products to produce high value-added products, Siberian sturgeon (Acipenser baerii) cartilages were degreased, mineralized, and separately hydrolyzed by five kinds of proteases. The collagen hydrolysate (SCH) generated by Alcalase showed the strongest 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·) and hydroxide radical (HO·) scavenging activity. Subsequently, thirteen antioxidant peptides (SCP1-SCP3) were isolated from SCH, and they were identified as GPTGED, GEPGEQ, GPEGPAG, VPPQD, GLEDHA, GDRGAEG, PRGFRGPV, GEYGFE, GFIGFNG, PSVSLT, IELFPGLP, LRGEAGL, and RGEPGL with molecular weights of 574.55, 615.60, 583.60, 554.60, 640.64, 660.64, 885.04, 700.70, 710.79, 602.67, 942.12, 714.82, and 627.70 Da, respectively. GEYGFE, PSVSLT, and IELFPGLP showed the highest scavenging activity on DPPH· (EC50: 1.27, 1.05, and 1.38 mg/mL, respectively) and HO· (EC50: 1.16, 0.97, and 1.63 mg/mL, respectively), inhibiting capability of lipid peroxidation, and protective functions on H2O2-damaged plasmid DNA. More importantly, GEYGFE, PSVSLT, and IELFPGLP displayed significant cytoprotection on HUVECs against H2O2 injury by regulating the endogenous antioxidant enzymes of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) to decrease the contents of reactive oxygen species (ROS) and malondialdehyde (MDA). Therefore, the research provided better technical assistance for a higher-value utilization of Siberian sturgeon cartilages and the thirteen isolated peptides—especially GEYGFE, PSVSLT, and IELFPGLP—which may serve as antioxidant additives for generating health-prone products to treat chronic diseases caused by oxidative stress.
      Citation: Marine Drugs
      PubDate: 2022-05-14
      DOI: 10.3390/md20050325
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 326: Metabolic Profiling and In Vitro
           Assessment of the Biological Activities of the Ethyl Acetate Extract of
           Penicillium chrysogenum “Endozoic of Cliona sp. Marine Sponge”
           from the Red Sea (Egypt)

    • Authors: Muneera S. M. Al-Saleem, Wafaa H. B. Hassan, Zeinab I. El Sayed, Mahmoud M. Abdel-Aal, Wael M. Abdel-Mageed, Eman Abdelsalam, Sahar Abdelaziz
      First page: 326
      Abstract: Marine sponge-derived endozoic fungi have been gaining increasing importance as promising sources of numerous and unique bioactive compounds. This study investigates the phytochemical profile and biological activities of the ethyl acetate extract of Penicillium chrysogenum derived from Cliona sp. sponge. Thirty-six compounds were tentatively identified from P. chrysogenum ethyl acetate extract along with the kojic acid (KA) isolation. The UPLC-ESI-MS/MS positive ionization mode was used to analyze and identify the extract constituents while 1D and 2D NMR spectroscopy were used for kojic acid (KA) structure confirmation. The antimicrobial, antioxidant, and cytotoxic activities were assessed in vitro. Both the extract and kojic acid showed potent antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa with MIC 250 ± 0.82 µg/mL. Interestingly, the extract showed strong antifungal activity against Candida albicans and Cryptococcus neoformans with MIC 93.75 ± 0.55 and 19.53 ± 0.48 µg/mL, respectively. Furthermore, KA showed the same potency against Fusarium oxysporum and Cryptococcus neoformans with MIC 39.06 ± 0.85 and 39.06 ± 0.98 µg/mL, respectively. Ultimately, KA showed strong antioxidant activity with IC50 33.7 ± 0.8 µg/mL. Moreover, the extract and KA showed strong cytotoxic activity against colon carcinoma (with IC50 22.6 ± 0.8 and 23.4 ± 1.4 µg/mL, respectively) and human larynx carcinoma (with equal IC50 30.8 ± 1.3 and ± 2.1 µg/mL, respectively), respectively. The current study represents the first insights into the phytochemical profile and biological properties of P. chrysoenum ethyl acetate extract, which could be a promising source of valuable secondary metabolites with potent biological potentials.
      Citation: Marine Drugs
      PubDate: 2022-05-15
      DOI: 10.3390/md20050326
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 327: Humic Substances as Microalgal
           Biostimulants—Implications for Microalgal Biotechnology

    • Authors: Daria Gabriela Popa, Carmen Lupu, Diana Constantinescu-Aruxandei, Florin Oancea
      First page: 327
      Abstract: Humic substances (HS) act as biostimulants for terrestrial photosynthetic organisms. Their effects on plants are related to specific HS features: pH and redox buffering activities, (pseudo)emulsifying and surfactant characteristics, capacity to bind metallic ions and to encapsulate labile hydrophobic molecules, ability to adsorb to the wall structures of cells. The specific properties of HS result from the complexity of their supramolecular structure. This structure is more dynamic in aqueous solutions/suspensions than in soil, which enhances the specific characteristics of HS. Therefore, HS effects on microalgae are more pronounced than on terrestrial plants. The reported HS effects on microalgae include increased ionic nutrient availability, improved protection against abiotic stress, including against various chemical pollutants and ionic species of potentially toxic elements, higher accumulation of value-added ingredients, and enhanced bio-flocculation. These HS effects are similar to those on terrestrial plants and could be considered microalgal biostimulant effects. Such biostimulant effects are underutilized in current microalgal biotechnology. This review presents knowledge related to interactions between microalgae and humic substances and analyzes the potential of HS to enhance the productivity and profitability of microalgal biotechnology.
      Citation: Marine Drugs
      PubDate: 2022-05-16
      DOI: 10.3390/md20050327
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 328: An Octopus-Derived Peptide with
           Antidiuretic Activity in Rats

    • Authors: Ye-Ji Kim, Jei Ha Lee, Seung-Hyun Jung, Ki Hyun Kim, Chang-Hoon Choi, Seonmi Jo, Dong Ho Woo
      First page: 328
      Abstract: Discovering new drug candidates with high efficacy and few side effects is a major challenge in new drug development. The two evolutionarily related peptides oxytocin (OXT) and arginine vasopressin (AVP) are known to be associated with a variety of physiological and psychological processes via the association of OXT with three types of AVP receptors. Over decades, many synthetic analogs of these peptides have been designed and tested for therapeutic applications; however, only a few studies of their natural analogs have been performed. In this study, we investigated the bioactivity and usefulness of two natural OXT/AVP analogs that originate from the marine invertebrate Octopus vulgaris, named octopressin (OTP) and cephalotocin (CPT). By measuring the intracellular Ca2+ or cyclic AMP increase in each OXT/AVP receptor subtype–overexpressing cell, we found that CPT, but not OTP, acts as a selective agonist of human AVP type 1b and 2 receptors. This behavior is reminiscent of desmopressin, the most widely prescribed antidiuretic drug in the world. Similar to the case for desmopressin, a single intravenous tail injection of CPT into Sprague-Dawley rats reduced urine output and increased urinary osmolality. In conclusion, we suggest that CPT has a significant antidiuretic effect and that CPT might be beneficial for treating urological conditions such as nocturia, enuresis, and diabetes insipidus.
      Citation: Marine Drugs
      PubDate: 2022-05-17
      DOI: 10.3390/md20050328
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 329: A Medicinal Halophyte Ipomoea pes-caprae
           (Linn.) R. Br.: A Review of Its Botany, Traditional Uses, Phytochemistry,
           and Bioactivity

    • Authors: Ganiyu Akinniyi, Jeonghee Lee, Hiyoung Kim, Joon-Goo Lee, Inho Yang
      First page: 329
      Abstract: Ipomoea pes-caprae (Linn.) R. Br. (Convolvulaceae) is a halophytic plant that favorably grows in tropical and subtropical countries in Asia, America, Africa, and Australia. Even though this plant is considered a pan-tropical plant, I. pes-caprae has been found to occur in inland habitats and coasts of wider areas, such as Spain, Anguilla, South Africa, and Marshall Island, either through a purposeful introduction, accidentally by dispersal, or by spreading due to climate change. The plant parts are used in traditional medicine for treating a wide range of diseases, such as inflammation, gastrointestinal disorders, pain, and hypertension. Previous phytochemical analyses of the plant have revealed pharmacologically active components, such as alkaloids, glycosides, steroids, terpenoids, and flavonoids. These phytoconstituents are responsible for the wide range of biological activities possessed by I. pes-caprae plant parts and extracts. This review arranges the previous reports on the botany, distribution, traditional uses, chemical constituents, and biological activities of I. pes-caprae to facilitate further studies that would lead to the discovery of novel bioactive natural products from this halophyte.
      Citation: Marine Drugs
      PubDate: 2022-05-17
      DOI: 10.3390/md20050329
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 330: The Role of Seawater and Saline
           Solutions in Treatment of Upper Respiratory Conditions

    • Authors: Danijela Štanfel, Livije Kalogjera, Sergej V. Ryazantsev, Kristina Hlača, Elena Y. Radtsig, Rashidov Teimuraz, Pero Hrabač
      First page: 330
      Abstract: The history of saline nasal irrigation (SNI) is indeed a long one, beginning from the ancient Ayurvedic practices and gaining a foothold in the west at the beginning of the 20th century. Today, there is a growing number of papers covering the effects of SNI, from in vitro studies to randomized clinical trials and literature overviews. Based on the recommendations of most of the European and American professional associations, seawater, alone or in combination with other preparations, has its place in the treatment of numerous conditions of the upper respiratory tract (URT), primarily chronic (rhino)sinusitis, allergic rhinitis, acute URT infections and postoperative recovery. Additionally, taking into account its multiple mechanisms of action and mounting evidence from recent studies, locally applied seawater preparations may have an important role in the prevention of viral and bacterial infections of the URT. In this review we discuss results published in the past years focusing on seawater preparations and their use in clinical and everyday conditions, since such products provide the benefits of additional ions vs. saline, have an excellent safety profile and are recommended by most professional associations in the field of otorhinolaryngology.
      Citation: Marine Drugs
      PubDate: 2022-05-17
      DOI: 10.3390/md20050330
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 331: Cyclodepsipeptides: Isolation from
           Endophytic Fungi of Sarcophyton ehrenbergi and Verification of Their
           Larvicidal Activity via In-Vitro and In-Silico Studies

    • Authors: Abdel Nasser B. Singab, Nada M. Mostafa, Yasmin A. Elkhawas, Eman Al-Sayed, Mokhtar M. Bishr, Ahmed M. Elissawy, Mohamed S. Elnaggar, Iten M. Fawzy, Osama M. Salama, Yi-Hong Tsai, Fang-Rong Chang
      First page: 331
      Abstract: Culex pipiens mosquitoes are vectors to many viruses and can transmit diseases such as filariasis and avian malaria. The present study evaluated the larvicidal activity of marine-derived endophytic fungi Aspergillus nomius and Aspergillus flavus from the soft coral Sarcophyton ehrenbergi along with two known cyclodepsipeptide compounds, scopularide A (1) and B (2), isolated from A. flavus extract, against third-instar larvae of C. pipiens, using distilled water as a negative control and toosenedanin as a positive control. The structures of the isolated compounds were confirmed by various spectroscopic analyses. The lethal concentrations (LC50 and LC90) were calculated by probit analysis. Scopularide A was the most potent after 96 h treatment, with LC50 and LC90 values of 58.96 and 994.31 ppm, respectively, and with 82.66% mortality at a concentration of 300 ppm. To unravel the biochemical mechanism of the tested extracts and compounds, their effects against protease, chitinase, phenoloxidases and lipase enzymes from the whole-body tissue of C. pipiens were evaluated after 72 h treatment at LC50 dose. Superior activity was observed for A. flavus extract against all tested enzymes. A molecular docking study was conducted for scopularide A and B on the four tested enzymes, to further verify the observed activity. Results revealed good binding affinities for both compounds as compared to the docked ligands, mainly via a number of hydrogen bonds. This was the first study to report the isolation of endophytic fungi A. flavus and A. nomius from the marine soft coral S. ehrenbergi. The endophytic fungal extract of A. flavus was found to be a promising source for a natural larvicidal agent against C. pipiens populations.
      Citation: Marine Drugs
      PubDate: 2022-05-18
      DOI: 10.3390/md20050331
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 332: Ferroptosis Related Immunomodulatory
           Effect of a Novel Extracellular Polysaccharides from Marine Fungus
           Aureobasidium melanogenum

    • Authors: Yuqi Lin, Jiajia Yang, Lianxiang Luo, Xiaoyong Zhang, Shengyu Deng, Xiaodan Chen, Yiyang Li, Alaa El-Din A. Bekhit, Baojun Xu, Riming Huang
      First page: 332
      Abstract: Marine fungi represent an important and sustainable resource, from which the search for novel biological substances for application in the pharmacy or food industry offers great potential. In our research, novel polysaccharide (AUM-1) was obtained from marine Aureobasidium melanogenum SCAU-266 were obtained and the molecular weight of AUM-1 was determined to be 8000 Da with 97.30% of glucose, 1.9% of mannose, and 0.08% galactose, owing to a potential backbone of α-D-Glcp-(1→2)-α-D-Manp-(1→4)-α-D-Glcp-(1→6)-(SO3−)-4-α-D-Glcp-(1→6)-1-β-D-Glcp-1→2)-α-D-Glcp-(1→6)-β-D-Glcp-1→6)-α-D-Glcp-1→4)-α-D-Glcp-6→1)-[α-D-Glcp-4]26→1)-α-D-Glcp and two side chains that consisted of α-D-Glcp-1 and α-D-Glcp-(1→6)-α-D-Glcp residues. The immunomodulatory effect of AUM-1 was identified. Then, the potential molecular mechanism by which AUM-1 may be connected to ferroptosis was indicated by metabonomics, and the expression of COX2, SLC7A11, GPX4, ACSL4, FTH1, and ROS were further verified. Thus, we first speculated that AUM-1 has a potential effect on the ferroptosis-related immunomodulatory property in RAW 264.7 cells by adjusting the expression of GPX4, regulated glutathione (oxidative), directly causing lipid peroxidation owing to the higher ROS level through the glutamate metabolism and TCA cycle. Thus, the ferroptosis related immunomodulatory effect of AUM-1 was obtained.
      Citation: Marine Drugs
      PubDate: 2022-05-19
      DOI: 10.3390/md20050332
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 333: Approaches to Configuration
           Determinations of Flexible Marine Natural Products: Advances and Prospects

    • Authors: Zong-Qing Huo, Feng Zhu, Xing-Wang Zhang, Xiao Zhang, Hong-Bao Liang, Jing-Chun Yao, Zhong Liu, Gui-Min Zhang, Qing-Qiang Yao, Guo-Fei Qin
      First page: 333
      Abstract: Flexible marine natural products (MNPs), such as eribulin and bryostatin, play an important role in the development of modern marine drugs. However, due to the multiple chiral centers and geometrical uncertainty of flexible systems, configuration determinations of flexible MNPs face great challenges, which, in turn, have led to obstacles in druggability research. To resolve this issue, the comprehensive use of multiple methods is necessary. Additionally, configuration assignment methods, such as X-ray single-crystal diffraction (crystalline derivatives, crystallization chaperones, and crystalline sponges), NMR-based methods (JBCA and Mosher’s method), circular dichroism-based methods (ECCD and ICD), quantum computational chemistry-based methods (NMR calculations, ECD calculations, and VCD calculations), and chemical transformation-based methods should be summarized. This paper reviews the basic principles, characteristics, and applicability of the methods mentioned above as well as application examples to broaden the research and applications of these methods and to provide a reference for the configuration determinations of flexible MNPs.
      Citation: Marine Drugs
      PubDate: 2022-05-19
      DOI: 10.3390/md20050333
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 334: Bioactivity-Guided Screening of
           Antimicrobial Secondary Metabolites from Antarctic Cultivable Fungus
           Acrostalagmus luteoalbus CH-6 Combined with Molecular Networking

    • Authors: Ting Shi, Xiang-Qian Li, Ze-Min Wang, Li Zheng, Yan-Yan Yu, Jia-Jia Dai, Da-Yong Shi
      First page: 334
      Abstract: With the increasingly serious antimicrobial resistance, discovering novel antibiotics has grown impendency. The Antarctic abundant microbial resources, especially fungi, can produce unique bioactive compounds for adapting to the hostile environment. In this study, three Antarctic fungi, Chrysosporium sp. HSXSD-11-1, Cladosporium sp. HSXSD-12 and Acrostalagmus luteoalbus CH-6, were found to have the potential to produce antimicrobial compounds. Furthermore, the crude extracts of CH-6 displayed the strongest antimicrobial activities with 72.3–84.8% growth inhibition against C. albicans and Aeromonas salmonicida. The secondary metabolites of CH-6 were researched by bioactivity tracking combined with molecular networking and led to the isolation of two new α-pyrones, acrostalapyrones A (1) and B (2), along with one known analog (3), and three known indole diketopiperazines (4–6). The absolute configurations of 1 and 2 were identified through modified Mosher’s method. Compounds 4 and 6 showed strong antimicrobial activities. Remarkably, the antibacterial activity of 6 against A. salmonicida displayed two times higher than that of the positive drug Ciprofloxacin. This is the first report to discover α-pyrones from the genus Acrostalagmus, and the significant antimicrobial activities of 4 and 6 against C. albicans and A. salmonicida. This study further demonstrates the great potential of Antarctic fungi in the development of new compounds and antibiotics.
      Citation: Marine Drugs
      PubDate: 2022-05-19
      DOI: 10.3390/md20050334
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 335: Multiple Roles of Chitosan in Mucosal
           Drug Delivery: An Updated Review

    • Authors: Paola Mura, Francesca Maestrelli, Marzia Cirri, Natascia Mennini
      First page: 335
      Abstract: Chitosan (CS) is a linear polysaccharide obtained by the deacetylation of chitin, which, after cellulose, is the second biopolymer most abundant in nature, being the primary component of the exoskeleton of crustaceans and insects. Since joining the pharmaceutical field, in the early 1990s, CS attracted great interest, which has constantly increased over the years, due to its several beneficial and favorable features, including large availability, biocompatibility, biodegradability, non-toxicity, simplicity of chemical modifications, mucoadhesion and permeation enhancer power, joined to its capability of forming films, hydrogels and micro- and nanoparticles. Moreover, its cationic character, which renders it unique among biodegradable polymers, is responsible for the ability of CS to strongly interact with different types of molecules and for its intrinsic antimicrobial, anti-inflammatory and hemostatic activities. However, its pH-dependent solubility and susceptibility to ions presence may represent serious drawbacks and require suitable strategies to be overcome. Presently, CS and its derivatives are widely investigated for a great variety of pharmaceutical applications, particularly in drug delivery. Among the alternative routes to overcome the problems related to the classic oral drug administration, the mucosal route is becoming the favorite non-invasive delivery pathway. This review aims to provide an updated overview of the applications of CS and its derivatives in novel formulations intended for different methods of mucosal drug delivery.
      Citation: Marine Drugs
      PubDate: 2022-05-20
      DOI: 10.3390/md20050335
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 336: Exopolysaccharides from Microalgae and
           Cyanobacteria: Diversity of Strains, Production Strategies, and

    • Authors: Céline Laroche
      First page: 336
      Abstract: Microalgae and cyanobacteria are photosynthetic organisms that can produce/accumulate biomolecules with industrial interest. Among these molecules, EPSs are macromolecular polysaccharidic compounds that present biological activities and physico-chemical properties, allowing to consider their valorization in diverse commercial markets, such as cosmetic, therapeutic, nutraceutic, or hydrocolloids areas. The number of microalgae and cyanobacteria strains described to produce such EPSs has increased in recent years as, among the 256 producing strains gathered in this review, 86 were published in the last 10 years (~33%). Moreover, with the rise of research on microalgae EPSs, a variety of monosaccharides compositions have been discovered, highlighting the versatility of these organisms. If some production strategies can be applied to increase EPS production yields, it appears that case by case studies are needed to promote EPS synthesis by a strain, as many responses exist. This paper proposes an up-to-date state of the art of the diversity of microalgae and cyanobacteria EPS-producing strains, associated to the variability of compositions. The strategies for the production and extraction of the polymers are also discussed. Finally, an overview of the biological activities and physico-chemical properties allow one to consider their use on several commercial markets.
      Citation: Marine Drugs
      PubDate: 2022-05-21
      DOI: 10.3390/md20050336
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 337: Secondary Metabolites Isolated from
           Chilean Marine Algae: A Review

    • Authors: Dioni Arrieche, Héctor Carrasco, Andrés F. Olea, Luis Espinoza, Aurelio San-Martín, Lautaro Taborga
      First page: 337
      Abstract: Chile is in the extreme southwestern part of America, and it has an extreme length, of approximately 4300 km that increases to 8000 km considering the Chilean Antarctic Territory. Despite the large extent of its coastal territory and the diversity of geographic environments and climates associated with Chilean coasts, the research on marine resources in Chile has been rather scarce. From marine organisms found in Chilean coastal waters, algae have been the most studied, since they contain a wide range of interesting secondary metabolites that have some structural traits that make them unique and uncharacteristic. Thus, a wide structural variety of natural products including terpenoids (monoterpenes, sesquiterpenes, diterpenes, and meroterpenoids), furanones, and C15-acetogenins have been isolated and identified. This review describes the existing literature on bioprospecting and exploration of secondary metabolites from Chilean coasts.
      Citation: Marine Drugs
      PubDate: 2022-05-23
      DOI: 10.3390/md20050337
      Issue No: Vol. 20, No. 5 (2022)
  • Marine Drugs, Vol. 20, Pages 338: Brasilterpenes A–E, Bergamotane
           Sesquiterpenoid Derivatives with Hypoglycemic Activity from the Deep
           Sea-Derived Fungus Paraconiothyrium brasiliense HDN15-135

    • Authors: Wenxue Wang, Yeqin Shi, Yuanyuan Liu, Yundong Zhang, Jiajin Wu, Guojian Zhang, Qian Che, Tianjiao Zhu, Mingyu Li, Dehai Li
      First page: 338
      Abstract: Five bergamotane sesquiterpenoid derivatives, brasilterpenes A–E (1–5), bearing an unreported spiral 6/4/5 tricyclic ring system, were isolated from the deep sea-derived ascomycete fungus Paraconiothyrium brasiliense HDN15-135. Their structures, including absolute configurations, were established by extensive spectroscopic methods complemented by single-crystal X-ray diffraction analyses, electronic circular dichroism (ECD), and density-functional theory (DFT) calculations of nuclear magnetic resonance (NMR) data including DP4+ analysis. The hypoglycemic activity of these compounds was assessed using a diabetic zebrafish model. Brasilterpenes A (1) and C (3) significantly reduced free blood glucose in hyperglycemic zebrafish in vivo by improving insulin sensitivity and suppressing gluconeogenesis. Moreover, the hypoglycemic activity of compound 3 was comparable to the positive control, anti-diabetes drug rosiglitazone. These results suggested brasilterpene C (3) had promising anti-diabetes potential.
      Citation: Marine Drugs
      PubDate: 2022-05-23
      DOI: 10.3390/md20050338
      Issue No: Vol. 20, No. 5 (2022)
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