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  Subjects -> CHEMISTRY (Total: 922 journals)
    - ANALYTICAL CHEMISTRY (56 journals)
    - CHEMISTRY (656 journals)
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    - INORGANIC CHEMISTRY (43 journals)
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    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (656 journals)            First | 1 2 3 4 | Last

Showing 401 - 600 of 735 Journals sorted alphabetically
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 2)
Journal of Pure and Applied Chemistry Research     Open Access   (Followers: 3)
Journal of Raman Spectroscopy     Hybrid Journal   (Followers: 17)
Journal of Research Updates in Polymer Science     Hybrid Journal   (Followers: 3)
Journal of Saudi Chemical Society     Open Access  
Journal of Solid State Chemistry     Hybrid Journal   (Followers: 14)
Journal of Solution Chemistry     Hybrid Journal   (Followers: 2)
Journal of Structural Chemistry     Hybrid Journal   (Followers: 1)
Journal of Sulfur Chemistry     Hybrid Journal   (Followers: 3)
Journal of Supercritical Fluids     Hybrid Journal   (Followers: 4)
Journal of Superhard Materials     Hybrid Journal   (Followers: 1)
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   (Followers: 1)
Journal of the American Chemical Society     Hybrid Journal   (Followers: 373)
Journal of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 32)
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 3)
Journal of the Bangladesh Chemical Society     Open Access  
Journal of the Chilean Chemical Society     Open Access   (Followers: 2)
Journal of the Iranian Chemical Society     Hybrid Journal  
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal   (Followers: 1)
Journal of the Mexican Chemical Society     Open Access   (Followers: 2)
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: 10)
JPC - Journal of Planar Chromatography - Modern TLC     Full-text available via subscription   (Followers: 2)
Jurnal Inovasi Pendidikan Kimia     Open Access   (Followers: 5)
Jurnal Katalisator     Open Access  
Jurnal Kimia (Journal of Chemistry)     Open Access  
Jurnal Kimia Riset     Open Access  
Jurnal Penelitian Sains (JPS)     Open Access  
Karadeniz Chemical Science and Technology     Open Access  
Karbala International Journal of Modern Science     Open Access   (Followers: 3)
Kinetics and Catalysis     Hybrid Journal   (Followers: 5)
Konfigurasi : Jurnal Pendidikan Kimia dan Terapan     Open Access  
Korea-Australia Rheology Journal     Hybrid Journal  
Langmuir     Hybrid Journal   (Followers: 63)
Latvian Journal of Chemistry     Open Access   (Followers: 1)
Lebensmittelchemie     Hybrid Journal   (Followers: 1)
Lipid Insights     Open Access  
Luminescence     Hybrid Journal   (Followers: 5)
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: 50)
Maghrebian Journal of Pure and Applied Science     Full-text available via subscription  
Magnetic Resonance in Chemistry     Hybrid Journal   (Followers: 10)
Magnetochemistry     Open Access  
Marine Chemistry     Hybrid Journal   (Followers: 7)
Marine Drugs     Open Access   (Followers: 4)
MATEC Web of Conferences     Open Access   (Followers: 5)
Materials Characterization     Hybrid Journal   (Followers: 34)
Materials Chemistry Frontiers     Full-text available via subscription  
Materials Horizons     Full-text available via subscription   (Followers: 3)
Materials Research Bulletin     Hybrid Journal   (Followers: 28)
Materials Science Monographs     Full-text available via subscription   (Followers: 3)
Materials Science-Poland     Open Access   (Followers: 1)
Materials Sciences and Applications     Open Access   (Followers: 3)
MedChemComm     Full-text available via subscription   (Followers: 7)
Medicinal Chemistry Research     Hybrid Journal   (Followers: 13)
Mediterranean Journal of Chemistry     Open Access  
Metallography, Microstructure, and Analysis     Hybrid Journal   (Followers: 2)
Metallomics     Full-text available via subscription  
Micro and Nano Systems Letters     Open Access   (Followers: 6)
Microchimica Acta     Hybrid Journal   (Followers: 2)
Microporous and Mesoporous Materials     Hybrid Journal   (Followers: 10)
Modern Chemistry & Applications     Open Access   (Followers: 1)
Modern Research in Catalysis     Open Access   (Followers: 1)
Molbank     Open Access   (Followers: 1)
Molecular Astrophysics     Full-text available via subscription  
Molecules     Open Access   (Followers: 7)
Molecules and Cells     Hybrid Journal   (Followers: 1)
Monatshefte für Chemie - Chemical Monthly     Hybrid Journal   (Followers: 4)
Mongolian Journal of Chemistry     Open Access  
Moroccan Journal of Chemistry     Open Access  
Moroccan Journal of Heterocyclic Chemistry     Open Access  
Moscow University Chemistry Bulletin     Hybrid Journal   (Followers: 1)
MRS Bulletin     Full-text available via subscription   (Followers: 4)
MRS Online Proceedings     Full-text available via subscription   (Followers: 1)
Nachrichten aus der Chemie     Hybrid Journal   (Followers: 17)
Nano Convergence     Open Access   (Followers: 1)
Nano Reviews & Experiments     Open Access   (Followers: 14)
Nanochemistry Research     Open Access  
Nanocontainers     Open Access   (Followers: 1)
Nanomaterials and the Environment     Open Access   (Followers: 1)
Nanoscale     Full-text available via subscription   (Followers: 20)
Nanoscale Advances     Open Access   (Followers: 1)
Nanoscale Research Letters     Open Access   (Followers: 9)
Nanoscience and Nanotechnology Letters     Full-text available via subscription   (Followers: 22)
Nanospectroscopy     Open Access   (Followers: 2)
Natural Product Reports     Full-text available via subscription   (Followers: 11)
Natural Products Chemistry & Research     Open Access   (Followers: 1)
Natural Products Journal     Hybrid Journal   (Followers: 1)
Natural Science     Open Access   (Followers: 9)
Natural Volatiles & Essential Oils     Open Access  
Nature Chemistry     Full-text available via subscription   (Followers: 95)
Nature Protocols     Full-text available via subscription   (Followers: 70)
Nature Reviews Chemistry     Hybrid Journal   (Followers: 7)
New Journal of Chemistry     Full-text available via subscription   (Followers: 19)
Nitric Oxide     Hybrid Journal  
Nitrogen     Open Access  
Nova Biotechnologica et Chimica     Open Access  
Nukleonika     Open Access   (Followers: 2)
Open Chemistry     Open Access   (Followers: 6)
Open Chemistry Journal     Open Access  
Open Conference Proceedings Journal     Open Access  
Open Journal of Composite Materials     Open Access   (Followers: 18)
Open Journal of Inorganic Non-metallic Materials     Open Access   (Followers: 4)
Open Journal of Medicinal Chemistry     Open Access   (Followers: 5)
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: 3)
Organic & Biomolecular Chemistry     Full-text available via subscription   (Followers: 75)
Organometallics     Hybrid Journal   (Followers: 22)
Organosulfur Chemistry     Full-text available via subscription  
Oxidation of Metals     Hybrid Journal   (Followers: 18)
Peptidomics     Open Access  
Pharmaceuticals     Open Access   (Followers: 6)
Pharmaceutics     Open Access   (Followers: 4)
Phosphorus, Sulfur, and Silicon and the Related Elements     Hybrid Journal   (Followers: 2)
Photochemistry and Photobiology     Hybrid Journal   (Followers: 4)
Physical Sciences Reviews     Hybrid Journal   (Followers: 1)
Physics and Materials Chemistry     Open Access   (Followers: 2)
Phytochemistry     Hybrid Journal   (Followers: 6)
Phytochemistry Letters     Full-text available via subscription   (Followers: 4)
Plasma     Open Access   (Followers: 2)
Plasma Chemistry and Plasma Processing     Hybrid Journal   (Followers: 6)
Polímeros : Ciência e Tecnologia     Open Access  
Polycyclic Aromatic Compounds     Hybrid Journal  
Polyhedron     Hybrid Journal   (Followers: 4)
Polymer Chemistry     Full-text available via subscription   (Followers: 25)
Polymer Degradation and Stability     Hybrid Journal   (Followers: 26)
Polymer Engineering & Science     Hybrid Journal   (Followers: 16)
Polymer Reviews     Hybrid Journal   (Followers: 35)
Polymer Science Series D     Hybrid Journal   (Followers: 4)
Polymer Testing     Hybrid Journal   (Followers: 109)
Polymer-Plastics Technology and Engineering     Hybrid Journal   (Followers: 5)
Polymers     Open Access   (Followers: 18)
Procedia Chemistry     Open Access  
Proceedings in Radiochemistry. A Supplement to Radiochimica Acta     Open Access   (Followers: 1)
Proceedings of the Combustion Institute     Full-text available via subscription   (Followers: 8)
Processes     Open Access  
Progress in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 1)
Progress in Lipid Research     Hybrid Journal   (Followers: 3)
Progress in Organic Coatings     Hybrid Journal   (Followers: 9)
Progress in Polymer Science     Full-text available via subscription   (Followers: 37)
Progress in Reaction Kinetics and Mechanism     Full-text available via subscription   (Followers: 2)
Progress in Solid State Chemistry     Full-text available via subscription   (Followers: 3)
Progress in Surface Science     Full-text available via subscription   (Followers: 4)
Protein Science     Hybrid Journal   (Followers: 46)
Pure and Applied Chemistry     Hybrid Journal   (Followers: 8)
Química Nova     Open Access  
Quimica Viva     Open Access  
Radiochemistry     Hybrid Journal   (Followers: 2)
Rapid Communications in Mass Spectrometry     Hybrid Journal   (Followers: 32)
Reaction Chemistry & Engineering     Hybrid Journal  
Reaction Kinetics, Mechanisms and Catalysis     Hybrid Journal   (Followers: 2)
Recent Advances in Phytochemistry     Full-text available via subscription   (Followers: 3)
Recyclable Catalysis     Open Access   (Followers: 2)
Reports in Theoretical Chemistry     Open Access  
Research and Reports in Medicinal Chemistry     Open Access   (Followers: 3)
Research Journal of Phytochemistry     Open Access   (Followers: 3)
Review Journal of Chemistry     Hybrid Journal  
Reviews in Chemical Engineering     Hybrid Journal   (Followers: 6)
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Reviews of Adhesion and Adhesives     Full-text available via subscription  
Revista CENIC. Ciencias Quimicas     Open Access   (Followers: 2)
Revista Ciências Exatas e Naturais : RECEN     Open Access  
Revista Colombiana de Química     Open Access   (Followers: 1)
Revista Cubana de Química     Open Access  
Revista de Ciencia y Tecnología     Open Access  
Revista de Ciencias     Open Access  
Revista de la Societat Catalana de Química     Open Access  
Revista Debates em Ensino de Química     Open Access  
Revista ION     Open Access  
Revista Química : ciência, tecnologia e sociedade     Open Access  
RHAZES : Green and Applied Chemistry     Open Access  
RSC Advances     Open Access   (Followers: 33)
Rubber Chemistry and Technology     Full-text available via subscription   (Followers: 2)
Russian Chemical Reviews     Full-text available via subscription   (Followers: 4)
Russian Journal of Bioorganic Chemistry     Hybrid Journal   (Followers: 2)
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)
Sciences & Technologie A : sciences exactes     Open Access  
Scientific Journal of Frontier Chemical Development     Open Access   (Followers: 1)
Scientific Reports     Open Access   (Followers: 73)
Sensors and Actuators B: Chemical     Hybrid Journal   (Followers: 17)
Separation & Purification Reviews     Hybrid Journal   (Followers: 8)
Separation Science and Technology     Hybrid Journal   (Followers: 14)
Separations     Open Access   (Followers: 6)
Silicon Chemistry     Hybrid Journal   (Followers: 2)
Smart Materials Research     Open Access   (Followers: 7)
Soft     Open Access  
Soft Nanoscience Letters     Open Access   (Followers: 2)

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Similar Journals
Journal Cover
Phytochemistry
Journal Prestige (SJR): 1.048
Citation Impact (citeScore): 3
Number of Followers: 6  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0031-9422
Published by Elsevier Homepage  [3185 journals]
  • Anthraquinones from Cassiae semen as thrombin inhibitors: in
           vitro and in silico studies
    • Abstract: Publication date: September 2019Source: Phytochemistry, Volume 165Author(s): Xiao Yu, Ling-Hua Wei, Jia-Kai Zhang, Tian-Ran Chen, Qiang Jin, Yi-Nan Wang, Shui-Jun Zhang, Tong-Yi Dou, Yun-Feng Cao, Wen-Zhi Guo, Guang-Bo Ge, Ling Yang Thrombin inhibitor therapy is one of the most effective therapeutic strategies for the prevention and treatment of cardiovascular and thrombotic diseases. Although several marketed direct thrombin inhibitors (DTIs) have been widely used in clinic, the potentially serious complications of these DTIs prompted the researchers to find more DTIs with improved safety profiles. Herein, we report that natural anthraquinones in Cassiae semen (the seed of Cassia obtusifolia L. or C. tora L.), including obtusifolin, obtusin, aurantio-obtusin and chryso-obtusin, display strong to moderate inhibition on human thrombin, with the IC50 values ranging from 9.08 μM to 27.88 μM. Further investigation on the inhibition kinetics demonstrates that these anthraquinones are mixed inhibitors against thrombin-mediated Z-GGRAMC acetate hydrolysis, while obtusifolin and aurantio-obtusin show strong thrombin inhibition capacity, with the Ki values of 9.63 μM and 10.30 μM, respectively. Docking simulations demonstrate that both obtusifolin and aurantio-obtusin can simultaneously bind on the catalytic cavity and the two anion binding exosites (ABE1 and ABE2), while the hydroxyl group at the C-7 site and the methoxyl group at the C-8 site can create key interactions with the amino acids surrounding the catalytic cavity via hydrogen bonding. All these findings suggest that obtusifolin and aurantio-obtusin are strong thrombin inhibitors possessing a unique anthraquinone skeleton, and could be used as lead compounds for the development of new thrombin inhibitors with improved properties.Graphical abstractImage 1
       
  • Oligostilbenes from the leaves of Gnetum latifolium and their biological
           potential to inhibit neuroinflammation
    • Abstract: Publication date: September 2019Source: Phytochemistry, Volume 165Author(s): Hyo Moon Cho, Thi Kim Quy Ha, Ha Thanh Tung Pham, Jin-Pyo An, Jungmoo Huh, Ba-Wool Lee, Hee Ju Lee, Won Keun Oh Oligostilbenes are polyphenol oligomers derived from resveratrol and are commonly produced by members of the Gnetaceae family, and many researchers have focused on their anti-inflammatory activities. The EtOAc fraction of a Gnetum latifolium extract showed inhibitory activity against neuroinflammation induced by the transfection of Aβ1-42 into microglial BV-2 cells. The bioassay-guided isolation of the 70% EtOH extract of this plant resulted in three previously undescribed resveratrol oligostilbenes and ten known stilbene derivatives. The structures of the isolated compounds were established based on extensive NMR spectroscopic analysis. The absolute configurations of the three undescribed compounds were confirmed by comparison with available compounds with known stereochemistry and by ECD calculations and molecular modelling. Latifoliols A and B are the first reported oligostilbenes with a bridged 3-oxabicyclo[3.3.0]octane moiety, and latifoliol C was formed by the condensation of gnemontanin G with oxyresveratrol. Moreover, the hypothetical biogenetic pathway of latifoliols A, B and C was proposed. The potential anti-inflammatory activities of the thirteen isolated compounds were tested by measuring their effect on the secreted NO concentrations induced by transfection with plasmids expressing the Aβ1-42 gene in the BV-2 cell line. Interestingly, cis- and trans-shegansu B and latifolol, whose structures contained double bonds, strongly inhibited NO secretion in BV-2 cells, supporting the double binding effect of the stilbene derivative on inhibitory activity.Graphical abstractImage 1
       
  • Lignans and sesquiterpene lactones from Hypochaeris radicata subsp.
           neapolitana (Asteraceae, Cichorieae)
    • Abstract: Publication date: September 2019Source: Phytochemistry, Volume 165Author(s): Oleksandr Shulha, Serhat Sezai Çiçek, Helle Wangensteen, Janina Kroes, Malte Mäder, Ulrich Girreser, Jandirk Sendker, Karin Jöhrer, Richard Greil, Wolfgang Schühly, Alfonso Mangoni, Laura Grauso, Christoph van Thriel, Christian Zidorn Four undescribed lignans and two undescribed sesquiterpenic acids, together with three known compounds (hypochoeroside C, hypochoeroside D, and 5-O-caffeoylshikimic acid) were isolated from the roots of Hypochaeris radicata subsp. neapolitana (Asteraceae, Cichorieae). The lignans were identified as 4-(3,4-dihydroxybenzyl)-2-(3,4-dihydroxyphenyl)tetrahydrofuran-3-carboxy-O-β-D-glucopyranoside, 4-(3,4-dihydroxybenzyl)-2-(3,4-dihydroxyphenyl)tetrahydrofuran-3-carboxy-O-β-D-glucopyranosyl-2′-O-methacrylate, (7S,8R,8′R)-7-(3,4-dihydroxyphenyl)-3′,4′-dihydroxy-7,8,7′,8′-tetrahydronaphtho [8,8′-c]furan-1(3H)-one, and (7S,8R,8′R)-7-(3,4-dihydroxyphenyl)-3′,4′-dihydroxy-8'-(hydroxymethyl)-7,8,7′,8′-tetrahydronaphthalen-8-carboxylic acid. The two sesquiterpenic acids were identified as the ring open precursors of hypochoerosides C and D. Structures were elucidated using NMR and HRMS. Absolute configurations of (7S,8R,8′R)-7-(3,4-dihydroxyphenyl)-3′,4′-dihydroxy-7,8,7′,8′-tetrahydronaphtho [8,8′-c]furan-1(3H)-one and (7S,8R,8′R)-7-(3,4-dihydroxyphenyl)-3′,4′-dihydroxy-8'-(hydroxymethyl)-7,8,7′,8′-tetrahydronaphthalen-8-carboxylic acid were determined using electronic circular dichroism (ECD) spectroscopy. 4-(3,4-dihydroxybenzyl)-2-(3,4-dihydroxyphenyl)tetrahydrofuran-3-carboxy-O-β-D-glucopyranoside was evaluated for its anti-proliferative activity against myeloma cell lines MM1S, U266, and NCI-H929 and showed cytotoxicity at 100 mM against MM1S strain. No neurotoxicity was observed for major compounds 4-(3,4-dihydroxybenzyl)-2-(3,4-dihydroxyphenyl)tetrahydrofuran-3-carboxy-O-β-D-glucopyranoside, hypochoeroside C, and hypochoeroside D in a fluorescence assay measuring neurite outgrowth in dorsal root ganglion (DRG) neurons. Additionally, compounds 4-(3,4-dihydroxybenzyl)-2-(3,4-dihydroxyphenyl)tetrahydrofuran-3-carboxy-O-β-D-glucopyranoside, hypochoeroside C, hypochoeroside D, and hypochoerosidic acid D were quantified in unstressed and drought-stressed plants using HPLC-DAD. Drought-stressed plants were found to contain lower concentrations of the lignan 4-(3,4-dihydroxybenzyl)-2-(3,4-dihydroxyphenyl)tetrahydrofuran-3-carboxy-O-β-D-glucopyranoside and sesquiterpene lactone hypochoeroside C.Graphical abstractImage 1
       
  • Anti-BACE1 and anti-AchE activities of undescribed
           spiro-dioxolane-containing meroterpenoids from the endophytic fungus
           Aspergillus terreus Thom
    • Abstract: Publication date: September 2019Source: Phytochemistry, Volume 165Author(s): Changxing Qi, Qun Zhou, Weixi Gao, Mengting Liu, Chunmei Chen, Xiao-Nian Li, Yongji Lai, Yuan Zhou, Dongyan Li, Zhengxi Hu, Hucheng Zhu, Yonghui Zhang Spiroterreusnoids A–F, six undescribed spiro-dioxolane-containing adducts bearing 3,5-dimethylorsellinic acid-based meroterpenoid and 2,3-butanediol moieties were isolated from the endophytic fungus Aspergillus terreus Thom from Tripterygium wilfordii Hook. f. (Celastraceae). The structures of these adducts were established by spectroscopy, single-crystal X-ray diffraction, and experimental electronic circular dichroism (ECD) measurements. Spiroterreusnoids A–F represent the first examples of adducts composed of 3,5-dimethylorsellinic acid-based meroterpenoids. It is noteworthy that spiroterreusnoids A–F possessing a spiro-dioxolane moiety exhibited potential abilities in inhibiting BACE1 (IC50 values ranging from 5.86 to 27.16 μM) and AchE (IC50 values ranging from 22.18 to 32.51 μM), while the other analogues without this fragment displayed no such activities. Taken together, spiroterreusnoids A–F represent the first multitargeted natural adducts that could inhibit BACE1 and AchE, and might provide a new template for the development of new anti-Alzheimer's disease drugs.Graphical abstractImage 1
       
  • Mangiterpenes A–C and 2′,3′-seco-manginoid C, four
           sesquiterpene/monoterpene–shikimate–conjugated spirocyclic
           meroterpenoids from Guignardia mangiferae
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Keliang Chen, Chunmei Chen, Jieru Guo, Weiguang Sun, Junjun Liu, Jing Yang, Xiulan Liu, Jianping Wang, Zengwei Luo, Hucheng Zhu, Yonghui Zhang Mangiterpenes A–C and 2′,3′-seco-manginoid C, four undescribed sesquiterpene/monoterpene–shikimate–conjugated meroterpenoids with spiro ring systems, were isolated from Guignardia mangiferae. The structures and absolute configurations of these compounds were established by comprehensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Mangiterpenes A–C represent the first examples of sesquiterpene–shikimate-conjugated spirocyclic meroterpenoids, and 2′,3′-seco-manginoid C features an unexpected 2′,3′-seco-manginoids skeleton. Mangiterpene C strongly inhibited the production of NO inducted by LPS, with an IC50 value of 5.97 μM. It showed an anti-inflammatory effect by means of blocking in the NF-κB signaling pathway and decreasing the expression of inflammatory mediators.Graphical abstractFour undescribed sesquiterpene/monoterpene–shikimate–conjugated meroterpenoids with spiro ring systems were isolated from Guignardia mangiferae.Image 1
       
  • Characterization and quantification of thiol-peptides in Arabidopsis
           thaliana using combined dilution and high sensitivity HPLC-ESI-MS-MS
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Erika Bellini, Marco Borsò, Camilla Betti, Laura Bruno, Andrea Andreucci, Monica Ruffini Castiglione, Alessandro Saba, Luigi Sanità di Toppi Although thiol-peptide compounds, such as reduced glutathione (GSH), γ-glutamylcysteine (γ-EC), and phytochelatins, play fundamental roles in plants, their analytical determination and characterization is still somewhat problematic, mainly due to their high polarity and oxidation propensity. Thus, in this work a reliable and sensitive HPLC-ESI-MS-MS method was developed, in order to simultaneously assay, within 14-min instrumental runs, γ-EC, GSH, and phytochelatins up to phytochelatin 4. This analytical method was validated in shoot and root extracts of the model plant Arabidopsis thaliana (Brassicaceae) and guaranteed accurate quantification by using specific isotope labelled-internal standards for both GSH and phytochelatins, as well as standards for external calibration. Good linearities in the method performance were observed (R > 0.99), with a dynamic range over three orders of magnitude in thiol-peptide concentrations. In MRM mode, the detection sensitivity of the thiol-peptides was equal to approximately 16, 6, 7, 13, 10 fmol for γ-EC, GSH, phytochelatin 2, phytochelatin 3, and phytochelatin 4, respectively (20 μl injection each). The reproducibility of the method was confirmed by high intra- and inter-day accuracy and precision values. The recovery rates were estimated approximately in the range of 73.8–91.0% and the matrix effect evaluation revealed that all analytes exhibited ionization suppression. The use of stable isotope-labelled analogs of the thiol-peptides as internal standards was particularly worthy of note: it offered the considerable advantage of overcoming the consequences of matrix effect and thiol-peptide loss through sample preparation, by normalizing the analyte signal during the quantification process. Thus, by validating the method's sensitivity, accuracy, precision, reproducibility, stability, recovery, and matrix effect, data reliability and robustness were ensured.Graphical abstractImage 1
       
  • Termipaniculatones A-F, chalcone-flavonone heterodimers from Terminthia
           paniculata, and their protective effects on hyperuricemia and acute gouty
           arthritis
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Tong-Hua Yang, De-Xiu Yan, Xiao-Yan Huang, Bo Hou, Yun-Bao Ma, Hua Peng, Xue-Mei Zhang, Ji-Jun Chen, Chang-An Geng Terminthia paniculata (Sanyeqi) is widely used for treating inflammation and rheumatic arthritis in the folk areas of Yunnan province, China. Its total extract was first revealed with xanthine oxidase (XO) inhibitory activity in vitro and anti-hyperuricemic effect in vivo. Bioassay-guided separation on Fr. A5 yielded six chalcone-flavonone heterodimers, termipaniculatones A-F. Their structures were elucidated based on extensive spectroscopic analyses involving HRESIMS, 1D and 2D NMR, UV, IR and [α]D, and the absolute configuration of termipaniculatone F was verified by ECD calculation. Termipaniculatones A and E showed obvious XO inhibitory activity with IC50 values of 55.6 and 89.5 μM, respectively, which took effects via a mix-type mode. A molecular modeling study revealed that termipaniculatone A was well located into the active site of XO by interacting with Glu802, Arg880, Thr1010 and Val1011 residues. Termipaniculatone A showed anti-hyperuricemic effects by decreasing serum uric acid levels and inhibiting XO activity in both serum and liver on potassium oxonate (PO)-induced hyperuricemia mice, and anti-inflammatory activity through alleviating paw swelling on monosodium urate (MSU)-induced mice, at the concentration of 20 mg/kg. This is the first time to reveal the anti-hyperuricemic and anti-acute gouty arthritis potency of T. paniculata and the characteristic biflavonoids as active constituents, which provides valuable information for searching new XO inhibitors from natural sources.Graphical abstractImage 1
       
  • Structure and bioactivity of cholestane glycosides from the bulbs of
           Ornithogalum saundersiae Baker
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Qing-Wei Chen, Xu Zhang, Ting Gong, Wan Gao, Shuai Yuan, Pei-Cheng Zhang, Jian-Qiang Kong Eight undescribed cholestane glycosides named osaundersioside A-H, along with three previously known compounds named osaundersioside I–K were isolated from Ornithogalum saundersiae Baker bulbs (Asparagaceae). Their structures were elucidated by extensive spectroscopic analysis and chemical methods. All isolates were evaluated for their cytotoxic activity and inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production. Osaundersioside C was thus determined to exhibit specific cytotoxicity towards MCF-7 cell line with an IC50 value of 0.20 μM, Osaundersioside H exhibited inhibitory effect on NO production in macrophages at the concentration of 10−5 M, with inhibition rate of 56.81%.Graphical abstractEight undescribed cholestane glycosides including osaundersioside C and H were isolated from Ornithogalum saundersiae Baker (Asparagaceae). Osaundersioside C exhibited specific cytotoxicity towards MCF-7 cell line and osaundersioside H showed inhibitory effect on NO production in macrophages.Image 105
       
  • Repurposing of ginseng extract as topoisomerase I inhibitor based on the
           comparative analysis of gene expression patterns
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Mi Ran Byun, Cheol Hyun Kim, Ho Sub Lee, Jin Woo Choi, Sang Kwan Lee Repositioning of plant extracts and chemical drugs can accelerate drug development. However, its success rate may depend on what the clue is for the repositioning. Recently, repositioning based on correction of unwarranted gene expression pattern has suggested the possibility of new drug development. Here, we designed a similar method for the repositioning of nutraceutical ginseng (Panax ginseng C.A.Mey.), which is one of the most validated natural therapeutic products for various diseases. We analyzed ginseng-induced gene expression profiles using the connectivity map algorithm, which is a database that connects diseases, chemical drugs, and gene expression. Ginseng was predicted to show the same effects as those of topoisomerase I inhibitors. In a subsequent in vitro assay, ginseng extract unwound coiled or supercoiled DNA, an effect comparable to that of the topoisomerase I inhibitor, camptothecin. Furthermore, ginseng extract induced synthetic lethality with suppression of the Werner syndrome gene. The collected data implicate ginseng as a candidate antitumor agent owing to its topoisomerase I inhibitory activity and further validate the usefulness of differentially expressed gene similarity-based repurposing of other natural products.Graphical abstract- Gene expression patterns between ginseng and other chemical drugs was compared. - The analysis revealed inhibitory effect of ginseng against topoisomerase I activity.Image 1
       
  • NMR characterization and evaluation of antibacterial and antiobiofilm
           activity of organic extracts from stationary phase batch cultures of five
           marine microalgae (Dunaliella sp., D. salina, Chaetoceros calcitrans, C.
           gracilis and Tisochrysis lutea)
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Ma José Iglesias, Raquel Soengas, Ian Probert, Emilie Guilloud, Priscillia Gourvil, Mohamed Mehiri, Yuly López, Virginio Cepas, Ignacio Gutiérrez-del-Río, Saúl Redondo-Blanco, Claudio J. Villar, Felipe Lombó, Sara Soto, Fernando López Ortiz The chemical composition of five marine microalgae (Dunaliella sp., Dunaliella salina, Chaetoceros calcitrans, Chaetoceros gracilis and Tisochrysis lutea) was investigated through nuclear magnetic resonance (NMR) spectroscopic study of the soluble material obtained by sequential extraction with hexane, ethyl acetate (AcOEt) and methanol of biomass from stationary phase cultures. Hexane extracted the major lipids present in the microalgae during the stationary phase of growth, which correspond to storage lipids. Triacylglycerols (TGs) were the only storage lipids produced by Dunaliella and Chaetoceros. In contrast, T. lutea predominantly stored polyunsaturated long-chain alkenones, with sterols also detected as minor components of the hexane extract. The molecular structure of brassicasterol was determined in T. lutea and the presence of squalene in this sample was also unequivocally detected. Monogalactosyldiacylglycerols (MGDGs) and pigments were concentrated in the AcOEt extracts. C. calcitrans and D. salina constituted an exception due to the high amount of TGs and glycerol produced, respectively, by these two strains. Chlorophylls a and b and β-carotene were the major pigments synthesized by Dunaliella and chlorophyll a and fucoxanthin were the only pigments detected in Chaetoceros and T. lutea. Information concerning the acyl chains present in TGs and MGDGs as well as the positional distribution of acyl chains on the glycerol moiety was obtained by NMR analysis of hexane and AcOEt extracts, with results consistent with those expected for the genera studied. Fatty acid composition of TGs in the two Dunaliella strains was different, with polyunsaturated acyl chains almost absent in the storage lipids produced by D. salina. Except in C. calcitrans, the polar nature of soluble compounds was inferred through the relative extraction yield using methanol as the extraction solvent. Glycerol was the major component of this fraction for the Dunaliella strains. In T. lutea 1,4/2,5-cyclohexanetetrol (CHT) and dimethylsulfoniopropionate (DMSP) preponderated. CHT was also the major polyol present in the Chaetoceros strains in which DMSP was not detected, but prominent signals of 2,3-dihydroxypropane-1-sulfonate (DHSP) were observed in the 1H NMR spectra of methanolic extracts. The presence of DHSP confirms the production of this metabolite by diatoms. In addition, several other minor compounds (digalactosyldiacyglycerols (DGDGs), sulphoquinovosyldiacylglycerols (SQDGs), amino acids, carbohydrates, scyllo-inositol, mannitol, lactic acid and homarine) were also identified in the methanolic extracts. The antibacterial and antibiofilm activities of the extracts were tested. The AcOEt extract from C. gracilis showed a moderate antibiofilm activity.Graphical abstractImage 1
       
  • Highly oxygenated meroterpenoids from the Antarctic fungus Aspergillus
           terreus
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Wenya Feng, Chunmei Chen, Shuyuan Mo, Changxing Qi, Jiaojiao Gong, Xiao-Nian Li, Qun Zhou, Yuan Zhou, Dongyan Li, Yongji Lai, Hucheng Zhu, Jianping Wang, Yonghui Zhang Eleven highly oxygenated meroterpenoids, named terreustoxins A−K, along with five known analogues, were isolated from the Antarctic fungus Aspergillus terreus. The structures and absolute configurations of these undescribed compounds were characterized by NMR spectroscopy, single-crystal X-ray crystallography, and ECD experiments. Terreustoxins A−D are the first examples of meroterpenoids with two ortho-hydroxy groups at C-6 and C-7 in the terretonins family. Terreustoxin C and terretonin inhibited the proliferation of Con A-induced murine T cells at the concentration of 10 μM.Graphical abstractImage 10542
       
  • Antiproliferative steroidal glycosides from rhizomes of Polygonatum
           sibiricum
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Di Zhou, Xuezheng Li, Wenhui Chang, Yueqing Han, Bo Liu, Gang Chen, Ning Li Screening assays showed that total glycoside-rich fraction (TG) of rhizomes of Polygonatum sibiricum unveiled remarkable anti-proliferative activities against three cancer cell lines (A549, HepG2, and Caco2). Activity-guided isolation of TG afforded seven undescribed steroidal glycosides (polygonosides 1–7), along with 24 known glycosides. Their structures were established by 1D and 2D NMR spectroscopic analyses, high-resolution mass spectrometry, and chemical evidence. The isolated steroidal glycosides were tested for their antiproliferative activities against A549, HepG2, and Caco2 cells. Compounds 8, 10, 11, and 16 possessed stronger anticancer activities against A549 cells than the positive control Bay (25.8 μM), with IC50 values ranging from 5.8 to 24.2 μM. Compound 10 reduced the expression of Blc-2 and pro-caspase3 and increased the production of Bax as determined by western blotting. Molecular docking experiment suggested that 10 bound stably to the BH3-binding groove of the Bcl-2 protein by hydrogen bond interactions. These compounds could be candidates for anticancer agents with cytotoxic activity.Graphical abstractImage 1
       
  • Sesquiterpenoids and mycotoxin swainsonine from the locoweed endophytic
           fungus Alternaria oxytropis
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Xiangmei Tan, Xiaoyan Zhang, Meng Yu, Yongtao Yu, Zhe Guo, Ting Gong, Shubin Niu, Jianchun Qin, Zhongmei Zou, Gang Ding Oxytropiols A-J, ten undescribed guaiane-type sesquiterpenoids, and the mycotoxin swainsonine (SW) were isolated from the locoweed endophytic fungus Alternaria oxytropis. The chemical structures of these sesquiterpenoids were elucidated on the basis of HR-ESI-MS and NMR data including 1H, 13C, HSQC, 1H-1H COSY, HMBC, and NOESY spectra, and the absolute configurations of these compounds were determined using a modified Mosher's method and X-ray diffraction spectroscopy. A possible biosynthetic pathway of these guaiane-type sesquiterpenoids is discussed, and proposed that post-modification oxidative enzymes might form these highly polyhydroxylated structures. Compound 1 displayed biological effects on the root growth of Arabidopsis thaliana, and SW displayed cytotoxicity against A549 and HeLa cancer cell lines.Graphical abstractImage 1
       
  • Biosynthesis of cannflavins A and B from Cannabis sativa L
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Kevin A Rea, José A. Casaretto, M. Sameer Al-Abdul-Wahid, Arjun Sukumaran, Jennifer Geddes-McAlister, Steven J. Rothstein, Tariq A. Akhtar In addition to the psychoactive constituents that are typically associated with Cannabis sativa L., there exist numerous other specialized metabolites in this plant that are believed to contribute to its medicinal versatility. This study focused on two such compounds, known as cannflavin A and cannflavin B. These prenylated flavonoids specifically accumulate in C. sativa and are known to exhibit potent anti-inflammatory activity in various animal cell models. However, almost nothing is known about their biosynthesis. Using a combination of phylogenomic and biochemical approaches, an aromatic prenyltransferase from C. sativa (CsPT3) was identified that catalyzes the regiospecific addition of either geranyl diphosphate (GPP) or dimethylallyl diphosphate (DMAPP) to the methylated flavone, chrysoeriol, to produce cannflavins A and B, respectively. Further evidence is presented for an O-methyltransferase (CsOMT21) encoded within the C. sativa genome that specifically converts the widespread plant flavone known as luteolin to chrysoeriol, both of which accumulate in C. sativa. These results therefore imply the following reaction sequence for cannflavins A and B biosynthesis: luteolin ► chrysoeriol ► cannflavin A and cannflavin B. Taken together, the identification of these two unique enzymes represent a branch point from the general flavonoid pathway in C. sativa and offer a tractable route towards metabolic engineering strategies that are designed to produce these two medicinally relevant Cannabis compounds.Graphical abstractImage 1
       
  • Identification and characterization of (+)-α-bisabolol and
           7-epi-silphiperfol-5-ene synthases from Artemisia abrotanum
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Paskorn Muangphrom, Momoka Misaki, Munenori Suzuki, Masaya Shimomura, Hideyuki Suzuki, Hikaru Seki, Toshiya Muranaka Triquinane is a type of sesquiterpenoid with a unique structure that contains a fused tricyclopentane ring and exhibits a wide range of bioactivities. Like other sesquiterpenoids, the first committed step in triquinane-type sesquiterpenoid biosynthesis is the cyclization of farnesyl pyrophosphate (FPP), a common precursor of all sesquiterpenoids, catalyzed by sesquiterpene synthase. Artemisia abrotanum L. (Asteraceae), a common plant used in the culinary and cosmetics industries, has been reported to accumulate high levels of triquinane silphiperfol-5-en-3-one A. This compound is potentially biosynthesized from the cyclization of FPP into 7-epi-silphiperfol-5-ene followed by a multi-step oxidation to silphiperfol-5-en-3-one A. In this study, we aimed to identify the sesquiterpene synthase responsible for the synthesis of 7-epi-silphiperfol-5-ene. We performed RNA sequencing of A. abrotanum leaves and gene candidates were mined by homology searches using the triquinane α-isocomene synthase of chamomile (MrTPS2) as query. After gene cloning, we obtained five variants of putative sesquiterpene synthase showing greater than 85% amino acid identity to MrTPS2 and greater than 95% amino acid identity to each other. Heterologous expression of these variants in a FPP-high-producing yeast strain revealed the first four variants to be (+)-α-bisabolol synthases (AabrBOS1–4). However, the fifth candidate cyclized FPP into 7-epi-silphiperfol-5-ene and can therefore be defined as a 7-epi-silphiperfol-5-ene synthase (AabrSPS). These findings revealed the first committed enzyme involved in silphiperfol-5-en-3-one A and (+)-α-bisabolol biosyntheses in A. abrotanum. Furthermore, the results of this study will be useful for enhancing the production of these compounds for further applications.Graphical abstractImage 1
       
  • Isotopic ratio outlier analysis improves metabolomics prediction of
           nitrogen treatment in maize
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Chris Vlahakis, Jan Hazebroek, Chris Beecher, Felice de Jong We evaluated Isotope Ratio Outlier Analysis (IROA) as a metabolome-wide internal standard approach to improve the quality of LC/MS data collected from a large-scale greenhouse experiment designed to metric the ability of metabolomics to model quantitatively nitrogen treatments. We further looked at how IROA would be incorporated into a metabolomics workflow. For this we compared IROA processed data with that generated without the benefit of metabolome-wide internal standards using our current tool, Genedata Expressionist, from the same raw LC/MS data files. In our experiment, 367 maize plants were grown from kernel in a greenhouse under controlled conditions. Plants were treated from germination on with varying concentrations of nutrient nitrogen as one (treatment) variable. A second variable was the presence of one of two transgenes. Metabolomics analysis of leaves was performed by LC/MS positive and negative electrospray ionization modes, and raw data were processed with both our routine and IROA protocols. IROA data analysis detected 184 metabolites in each ionization mode. Analysis without IROA yielded 281 metabolites in positive ionization mode and 172 in negative ionization mode. Data from both protocols were normalized for sample dry weight, location in the greenhouse, extraction batch, sample run order, and internal standard. Normalized results were subjected to partial least squares (PLS) analysis to model the relationship between the metabolome and nitrogen treatment. Without IROA, regression coefficients of 0.819 and 0.849 for positive and negative modes, respectively were achieved. The IROA protocol improved on the values, yielding regression coefficients of 0.876 and 0.879 for positive and negative modes, respectively. In addition, IROA corrected for detector saturation for several high abundant peaks. Our experiment demonstrates that incorporating IROA into an LC/MS metabolomics experiment improves data quality and facilitates more precise modeling of a biological response.Graphical abstractImage 1
       
  • Isolation of enantiomeric furolactones and furofurans from Rubus idaeus L.
           with neuroprotective activities
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Le Zhou, Feng-Ying Han, Li-Wei Lu, Guo-Dong Yao, Ying-Ying Zhang, Xiao-Bo Wang, Bin Lin, Xiao-Xiao Huang, Shao-Jiang Song A phytochemical study on the fruits of Rubus idaeus L. (Rosaceae) yielded eight pairs of enantiomeric lignans, including one undescribed furolactone named (−)-idaeusinol A and six undescribed furofuran derivatives named (+/−)-idaeusinol B–D. The structures of these isolated compounds were elucidated by spectroscopic analyses and a combination of computational techniques including gauge-independent atomic orbital (GIAO) calculation of 1D NMR data and TD-DFT calculation of electronic circular dichroism (ECD) spectra. Bioactivity screenings suggested that (+)-idaeusinol D exhibited the most significant protective effect against H2O2-induced neurotoxicity at the concentration of 25 μM. In contrast, (−)-idaeusinol D, as the enantiomer of (+)-idaeusinol D, showed no effect against H2O2-induced neurotoxicity at both 25 and 50 μM concentration.Graphical abstractEight pairs of enantiomeric lignans, including one undescribed furolactone and six undescribed furofuran derivatives were isolated from the fruit of Rubus idaeus. (+)-Idaeusinol D showed obvious neuroprotective activity at 25 μM concentration.Image 1
       
  • Phenylethanoid glycosides from the Schnabelia nepetifolia (Benth.)
           P.D.Cantino promote the proliferation of osteoblasts
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Hong-Tao Xu, Cheng-Gang Zhang, Yu-Qiong He, Song-Shan Shi, Yong-Li Wang, Gui-Xin Chou An investigation of the n-BuOH fraction of Schnabelia nepetifolia (Benth.) P.D.Cantino led to the isolation and identification of 12 undescribed phenylethanoid glycosides (nepetifosides A–L) and one undescribed phenylmethanoid glycoside (nepetifoside M), together with 23 known compounds. The structures of these compounds were determined by spectroscopic analyses including two-dimensional nuclear-magnetic-resonance (2D-NMR) spectroscopy and chemical-hydrolysis methods. Nepetifoside F exhibited strong activity that significantly increased osteoblast proliferation at three concentrations of 0.1, 1, and 10 μM. Moreover, nepetifoside C and nepetifoside D exhibited moderate activities in promoting the proliferation of osteoblasts at medium and high concentrations of 1 μM and 10 μM, respectively.Graphical abstractImage 1
       
  • Isolation and functional characterization of an antifungal hydrophilic
           peptide, Skh-AMP1, derived from Satureja khuzistanica leaves
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Soghra Khani, Sima Sadat Seyedjavadi, Hadi Zare-Zardini, Hamideh Mahmoodzadeh Hosseini, Mehdi Goudarzi, Shohreh Khatami, Jafar Amani, Abbas Ali Imani Fooladi, Mehdi Razzaghi-Abyaneh The increasing resistance of pathogenic fungi to conventional antifungal therapies is a major global health concern. Currently, antifungal peptides are receiving increasing attention as suitable candidates for antifungal drug discovery. In the present study, an antifungal peptide was isolated from Satureja khuzistanica by reverse phase-HPLC column and sequenced by de novo sequencing and Edman degradation. The peptide cytotoxicity on human red blood cells and HEK293 cells was assessed using hemolytic and MTT assays. The purified peptide had 25 amino acids with pI and net charge equal to 9.31 and + 2, respectively. According to the systematic nomenclature, this peptide was named Skh-AMP1. The peptide showed strong antifungal activity against pathogenic species of Aspergillus and Candida with MIC values of 19.8–23.4 μM and MFC values of 39.6–58.5 μM. Molecular modeling analysis predicted a α-helix conformation for Skh-AMP1 and the probable hydrophilic residues and hydrophobic regions in the peptide structure which may responsible for its antifungal activity. Skh-AMP1 preserved its stability at the pH of 7 and 8 and the temperatures of 30 and 40 °C. The peptide showed negligible hemolytic activity in the range of 0.19–2.1% at the concentrations of 3.6–72 μM. It has no obvious cytotoxicity against HEK293 cells at the MIC of 25.2 μM for the fungal growth. All together, these properties make Skh-AMP1 as a previously undescribed peptide a promising potential therapeutic agent to combat immerging fungal infections.Graphical abstractImage 1
       
  • Arsenolipids in the green alga Coccomyxa (Trebouxiophyceae,
           Chlorophyta)
    • Abstract: Publication date: Available online 23 May 2019Source: PhytochemistryAuthor(s): Tomáš Řezanka, Linda Nedbalová, Dovilė Barcytė, Milada Vítová, Karel Sigler Lipid-like compounds containing a dimethylarsinoyl group, i.e. Me2As(O)-, have been identified by liquid chromatography/inductively coupled plasma mass spectrometry (LC/ICP-MS) and non-aqueous reversed-phase high-performance liquid chromatography (positive and/or negative high-resolution tandem electrospray ionization mass spectrometry (NARP-HPLC/HR-ESI+(−)-MS/MS) from three strains of green algae of the genus Coccomyxa (Trebouxiophyceae, Chlorophyta). The algae were cultivated in a medium containing 10 g arsenic/L, i.e. 133.5 mmol/L of Na2HAsO4.7H2O. After extraction by methyl-tert-butyl ether (MTBE), total lipids were analyzed by ICP-MS or ESI-MS without any further separation or fractionation. A total of 39 molecular species of arsenic triacylglycerols (AsTAG), 15 arsenic phosphatidylcholines (AsPC), 8 arsenic phosphatidylethanolamines (AsPE), 6 arsenic phosphatidylinositols (AsPI), 2 arsenic phosphatidylglycerols (AsPG) and 5 unknown lipids (probably ceramides) were identified. The structures of all molecular species were confirmed by tandem MS. Dry matter of the individual strains contained different amounts of total arsenolipids, i.e. C. elongata CCALA 427 (0.32 mg/g), C. onubensis (1.48 mg/g), C. elongata S3 (2.13 mg/g). On the other hand, there were only slight differences between strains in the relative abundances of individual molecular species. Possible biosynthesis of long-chain lipids with the end group Me2As(O) has also been suggested.Graphical abstractLipidic compounds containing a dimethylarsinoyl group have been identified by LC/ICP-MS and NARP-HPLC/HR-ESI+(−)-MS/MS from three strains of green algae of the genus Coccomyxa (Trebouxiophyceae, Chlorophyta) cultivated at high concentration of disodium hydrogen arsenate.Image 1
       
  • Cytotoxic lignans from the stems of Herpetospermum pedunculosum
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Yingxiong Ma, Hong Wang, Rui Wang, Fancheng Meng, Zhaoyue Dong, Guowei Wang, Xiaozhong Lan, Hong Quan, Zhihua Liao, Min Chen A bioassay-guided chemical investigation on the ethyl acetate extract of the stems of Herpetospermum pedunculosum led to the isolation and identification of 22 lignans including 6 previously undescribed ones, herpetosiols A-F. Their structures including stereochemistries were elucidated by analysis of NMR, HRMS and ECD data. The in vitro cytotoxic activities of all isolates were studied against human gastric carcinoma SGC7901, lung carcinoma A549, breast carcinoma MDA-MB-231 and hepatocellular carcinoma HepG2 cell lines. Among them, eight lignans exhibited anti-proliferative effects against four tumor cell lines with IC50 ranging from 1.7 ± 0.1 to 32.6 ± 1.1 μM. Hedyotol-B displayed potent inhibitory effect with IC50 values of 1.7 ± 0.1 μM against SGC7901 and 6.1 ± 0.5 μM against A549, respectively.Graphical abstractImage 1
       
  • Analytical investigations on Boswellia occulta essential oils
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Marina Ayubova, Zahra Osman Guelleh, Moktar Osman Guelleh, Hugues Brévard, Nicolas Baldovini Three samples of Boswellia occulta gum resin (Grades I, II and III) were analyzed by GC-MS and GC-FID. Fifty constituents could be identified, and several of them were isolated by flash chromatography and characterized by NMR. The combinatorial synthesis of homologous series of reference constituents permitted the unambiguous identification of five 1-methoxyalkanes and one 1-methoxyalkene. In addition, we measured the 14C content of one sample of essential oil and of a methoxyalkanes rich fraction and demonstrated that the origin of these materials is totally natural.Graphical abstractThe essential oil of Boswellia occulta, a newly described species, was investigated by GC-MS analysis and by fractionation followed by structural analysis of some isolated constituents. 14C analysis of the main components demonstrated unambiguously the natural origin of these samples.Image 1
       
  • Immobilized α-amylase magnetic beads for ligand fishing: Proof of concept
           and identification of α-amylase inhibitors in Ginkgo biloba
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Malene J. Petersen, Rita de Cássia Lemos Lima, Louise Kjaerulff, Dan Staerk Diabetes mellitus is a widespread metabolic disorder that affects millions of people around the world. The disease is a major burden on both economic and social levels, and there is a need for improved drugs with fewer side effects in the management of the disease. Current methods for isolation of anti-diabetic lead compounds from complex mixtures suffer from low resolution and sensitivity, and there is a need for improved alternatives. In this work, magnetic ligand fishing combined with high-performance liquid chromatography – photodiode-array detection – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy (HPLC-PDA-HRMS-SPE-NMR) was developed and validated, with the aim of accelerating discovery of natural products targeting α-amylase. The enzyme was successfully immobilized onto magnetic beads and retained its catalytic activity for a period of 75 days, and the specificity of this method was successfully validated by testing the N-terminus coupled α-amylase immobilized magnetic beads on an artificial mixture. A proof of concept experiment, using a crude ethyl acetate extract of Ginkgo biloba leaves, proved that it was possible to fish out four α-amylase ligands. HPLC-PDA-HRMS-SPE-NMR analysis confirmed the presence of bilobetin, isoginkgetin, ginkgetin and sciadopitysin in the solutions resulting from α-amylase ligand fishing with Ginkgo biloba. IC50 curves revealed a reversed relationship between concentration of sciadopitysin and inhibition of α-amylase activity, suggesting that this compound activated the enzyme instead of inhibiting it.Graphical abstractα-Amylase, a target for lowering blood glucose in diabetic patients, were immobilized on magnetic beads, and shown to effectively fish out binders from crude Ginkgo biloba ethyl acetate extract.Image 1
       
  • Overcoming deterrent metabolites by gaining essential nutrients: A
           lichen/snail case study
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Alice Gadea, Maryvonne Charrier, Mathieu Fanuel, Philippe Clerc, Corentin Daugan, Aurélie Sauvager, Hélène Rogniaux, Joël Boustie, Anne-Cécile Le Lamer, Françoise Lohézic - Le Devehat Specialised metabolites in lichens are generally considered repellent compounds by consumers. Nevertheless, if the only food available is lichens rich in specialised metabolites, lichenophages must implement strategies to overcome the toxicity of these metabolites. Thus, the balance between phagostimulant nutrients and deterrent metabolites could play a key role in feeding preferences. To further understand lichen-gastropod interactions, we studied the feeding behaviour and consumption in Notodiscus hookeri, the land snail native to sub-Antarctic islands. The lichen Usnea taylorii was used because of its simple chemistry, its richness in usnic acid (specialised metabolite) and arabitol (primary metabolite) and its presence in snail habitats. Choice tests in arenas with intact lichens versus acetone-rinsed lichens were carried out to study the influence of specialised metabolites on snail behaviour and feeding preference. Simultaneously, usnic acid and arabitol were quantified and located within the lichen thallus using HPLC-DAD-MS and in situ imaging by mass spectrometry to assess whether their spatial distribution explained preferential snail grazing. No-choice feeding experiments, with the pure metabolites embedded in an artificial diet, defined a gradual gustatory response, from strong repellence (usnic acid) to high appetence (D-arabitol). This case study demonstrates that the nutritional activity of N. hookeri is governed by the chemical quality of the food and primarily by nutrient availability (arabitol), despite the presence of deterrent metabolite (usnic acid).Graphical abstractThe main primary and specialised metabolites in Usnea taylorii are in situ located by mass spectrometry imaging. Arabitol, which is highly palatable to the snail Notodiscus hookeri, counterbalances the deterrent effect of usnic acid and plays a key role in lichen-snail trophic interactions.Image 1
       
  • Phenylpropanoid derivatives from the fruit of Crataegus pinnatifida Bunge
           and their distinctive effects on human hepatoma cells
    • Abstract: Publication date: Available online 17 May 2019Source: PhytochemistryAuthor(s): Rui Guo, Xin-Yue Shang, Tian-Ming Lv, Guo-Dong Yao, Bin Lin, Xiao-Bo Wang, Xiao-Xiao Huang, Shao-Jiang Song Ten undescribed phenylpropanoid derivatives including four pairs of enantiomers and two 8–9′ linked neolignans, together with fifteen known ones were isolated from the fruit of Crataegus pinnatifida Bunge. Their structures were established by comprehensive spectroscopic analyses. Enantiomers were separated successfully by chiral chromatographic column and their absolute configurations were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The in vitro cytotoxicity of the isolates were evaluated against two human hepatocellular carcinoma, HepG2 and Hep3B cells. Among them, (±)-crataegusanoid A, (±)-crataegusanoid B and crataegusanoid F exhibited moderate cytotoxicity. Interestingly, the different absolute configurations of (±)-crataegusanoid A and B demonstrated enantioselective cytotoxicity in HepG2 cells. Further flow cytometry analysis indicated that both (−)-crataegusanoid A and (−)-crataegusanoid B performed more significant effects on cell apoptosis, autophagy, and cell cycle progression compared with their enantiomers (+)-crataegusanoid A and (+)-crataegusanoid B. In addition, the results revealed that these two pairs of enantiomers induced protective autophagy in HepG2 cells.Graphical abstractImage 1
       
  • Phenylpropanoid glycosides from the fruit of Lycium barbarum L.
           and their bioactivity
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Qing-Wen Li, Rui Zhang, Zheng-Qun Zhou, Wan-Yang Sun, Hong-Xia Fan, Ying Wang, Jia Xiao, Kwok-Fai So, Xin-Sheng Yao, Hao Gao Fifteen phenylpropanoid glycosides, including six undescribed compounds were isolated from the fruit of Lycium barbarum L. (Solanaceae) (goji or wolfberry). Their structures were identified by detailed spectroscopic analyses. Seven known compounds were firstly isolated from the genus Lycium, in which the 1D and 2D NMR data of one compound were reported for the first time. Notably, two undescribed compounds were a pair of rare tautomeric glycoside anomers characterized by the presence of free anomeric hydroxy. Antioxidant and hypoglycemic activities of all these compounds were assessed using DPPH radical scavenging, oxygen radical absorbance capacity (ORAC), and α-glucosidase inhibitory assays, respectively. These compounds showed different levels of oxygen radical absorbance capacity, and some isolates exhibited potent antioxidant activity with greater ORAC values than the positive control (EGCG).Graphical abstractImage 1
       
  • Cytotoxic saponins and other natural products from flowering tops of
           Narthecium ossifragum L
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Andrea Estefanía Carpinteyro Díaz, Lars Herfindal, Bendik Auran Rathe, Kristine Yttersian Sletta, Anni Vedeler, Svein Haavik, Torgils Fossen For more than four centuries, the intake of Narthecium ossifragum has been associated with poisoning in domesticated animals. Saponins occurring in flowering tops of the plant are considered to cause kidney damage in calves. At present, there are more than 30 papers on the saponins of N. ossifragum in the literature, although the structures of these compounds have hitherto not been determined. Here, we identify the saponins of N. ossifragum as sarsasapogenin, sarsasapogenin-3-O-β-galactopyranoside, sarsasapogenin-3-O-(2′-O-β-glucopyranosyl-β-galactopyranoside) and sarsasapogenin-3-O-(2′-O-β-glucopyranosyl-3′-O-α-arabinopyranosyl-β-galactopyranoside). Moreover, six aromatic natural products were isolated and characterized from the methanolic extract from flowers of N. ossifragum. Five of these aromatic compounds, chrysoeriol 6-C-β-arabinofuranoside-8-C-β-glucopyranoside, chrysoeriol 6-C-β-arabinopyranosyl-8-C-β-glucopyranoside, chrysoeriol 6-C-β-xylopyranosyl-8-C-β-galactopyranoside, chrysoeriol 6-C-β-galactopyranosyl-8-C-β-glucopyranoside and chrysoeriol 6-C-β-glucopyranosyl-8-C-β-galactopyranoside are undescribed. All compounds were tested for cytotoxicity in mammalian cell lines derived from the heart, kidney, and haematological tissues. The saponins exhibited cytotoxicity in the micromolar range, with proportionally increasing cytotoxicity with increasing number of glycosyl substituents. The most potent compound was the main saponin sarsasapogenin-3-O-(2′-O-β-glucopyranosyl-3′-O-α-arabinopyranosyl-β-galactopyranoside), which produced cell death at concentrations below 3–4 μM in all three cell lines tested. This indicates that the saponins are the toxicants mainly responsible for kidney damage observed in cattle after ingestion of N. ossifragum. Our findings also pave the way for analysis of individual compounds isolated during the biopsies of intoxicated animals.Graphical abstractCytotoxic saponins from flowering tops of Narthecium ossifragum L. Andrea Estefanía Carpinteyro Díaz, Lars Herfindal, Bendik Auran Rathe, Kristine Yttersian Sletta, Svein Haavik and Torgils FossenCytotoxic saponins toxic to kidney cells were characterized from the hepatotoxic plant Narthecium ossifragum.Image 1
       
  • Biosynthesis of methyl (E)-cinnamate in the liverwort Conocephalum
           salebrosum and evolution of cinnamic acid methyltransferase
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Chi Zhang, Xinlu Chen, Barbara Crandall-Stotler, Ping Qian, Tobias G. Köllner, Hong Guo, Feng Chen Methyl (E)-cinnamate is a specialized metabolite that occurs in a variety of land plants. In flowering plants, it is synthesized by cinnamic acid methyltransferase (CAMT) that belongs to the SABATH family. While rarely reported in bryophytes, methyl (E)-cinnamate is produced by some liverworts of the Conocephalum conicum complex, including C. salebrosum. In axenically grown thalli of C. salebrosum, methyl (E)-cinnamate was detected as the dominant compound. To characterize its biosynthesis, six full-length SABATH genes, which were designated CsSABATH1-6, were cloned from C. salebrosum. These six genes showed different levels of expression in the thalli of C. salebrosum. Next, CsSABATH1-6 were expressed in Escherichia coli to produce recombinant proteins, which were tested for methyltransferase activity with cinnamic acid and a few related compounds as substrates. Among the six SABATH proteins, CsSABATH6 exhibited the highest level of activity with cinnamic acid. It was renamed CsCAMT. The apparent Km value of CsCAMT using (E)-cinnamic acid as substrate was determined to be 50.5 μM. In contrast, CsSABATH4 was demonstrated to function as salicylic acid methyltransferase and was renamed CsSAMT. Interestingly, the CsCAMT gene from a sabinene-dominant chemotype of C. salebrosum is identical to that of the methyl (E)-cinnamate-dominant chemotype. Structure models for CsCAMT, CsSAMT and one flowering plant CAMT (ObCCMT1) in complex with (E)-cinnamic acid and salicylic acid were built, which provided structural explanations to substrate specificity of these three enzymes. In phylogenetic analysis, CsCAMT and ObCCMT1 were in different clades, implying that methyl (E)-cinnamate biosynthesis in bryophytes and flowering plants originated through convergent evolution.Graphical abstractCinnamic acid methyltransferase (CsCAMT) for making methyl (E)-cinnamate was identified in the liverwort Conocephalum salebrosum. Structural and phylogenetic analysis suggests that CsCAMT and its counterpart in flowering plants evolved independently.Image 1
       
  • Hyperforatins L–U: Prenylated acylphloroglucinols with a terminal double
           bond from Hypericum perforatum L. (St John's Wort)
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Yi Guo, Na Zhang, Xueyan Duan, Yunfang Cao, Yongbo Xue, Zengwei Luo, Hucheng Zhu, Chunmei Chen, Jianping Wang, Yonghui Zhang Hyperforatins L–U, ten undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) bearing a terminal double bond, together with a known compound hypericumoxide J, were isolated from the aerial parts of Hypericum perforatum L. Their structures were elucidated by spectroscopic methods, including HRESIMS, IR, UV, and NMR (1H, 13C, DEPT, HSQC, HMBC, 1H–1H COSY, and NOESY experiments). Their absolute configurations were determined by comprehensive analyses of their experimental ECD spectra in conjunction with a modified Mosher's method. Evaluation of their neuroprotective activities highlighted hyperforatin L, which displayed mild activity at a concentration of 10 μM.Graphical abstractTen undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) were isolated from Hypericum perforatum L., some of which were evaluated for their neuroprotective activities.Image 1
       
  • Compositional analysis of the essential oil of Boswellia dalzielii
           frankincense from West Africa reveals two major chemotypes
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Anjanette DeCarlo, Stephen Johnson, Kingsley I. Okeke-Agulu, Noura S. Dosoky, Sophia J. Wax, Moses S. Owolabi, William N. Setzer Frankincense, an oleoresin produced by Boswellia species, has historical medicinal and religious significance, and is today used extensively for its essential oil. Boswellia dalzielii, a species found in West Africa, is one of the few frankincense species for which there is no information on the oleoresin essential oil. In order to correct this deficiency, the chemical compositions of the essential oil hydrodistilled from 21 samples of oleoresin taken directly from B. dalzielii trees in northern Nigeria, were analyzed by gas chromatography – mass spectrometry as well as chiral gas chromatography. In addition, a hierarchical cluster analysis was performed on the essential oil compositions from the 21 oleoresin samples from northern Nigeria as well as two samples from Ghana. The essential oil fractions obtained by hydrodistillation of B. dalzielii oleoresins were dominated by α-pinene (21.7–76.6%), followed by α-thujene (2.0–17.6%), myrcene (up to 35.2%), p-cymene (0.3–15.6%), and limonene (1.1–32.9%). The levorotatory enantiomers predominated for the monoterpenes with 98.1 ± 1.5% (−)-α-thujene, 99.2 ± 0.5% (−)-α-pinene, and 96.8 ± 1.4% (−)-β-pinene. Limonene showed the largest variation in enantiomeric distribution [67.3 ± 12.1% (−)-limonene]. The cluster analysis revealed two major chemotypes, one dominated by α-pinene and one much rarer chemotype rich in myrcene.Graphical abstractImage 1
       
  • Cytotoxic phenolic constituents from Hypericum japonicum
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Wei Zhu, Jie Qiu, Yan-Rong Zeng, Ping Yi, Hua-Yong Lou, Jun-You Jian, Ming-Xing Zuo, Lian Duan, Wei Gu, Lie-Jun Huang, Yan-Mei Li, Chun-Mao Yuan, Xiao-Jiang Hao Nine undescribed compounds, including five xanthone derivatives, two flavonoids, one 2-pyrone derivative, and one undescribed naturally occurring compound, along with 30 known phenolic compounds, were isolated from Hypericum japonicum. In addition, hyperjaponols A and B were identified as racemates. The structures and absolute configurations of the undescribed compounds were determined by comprehensive MS, NMR spectroscopy, and electronic circular dichroism (ECD) calculations. The cytotoxic effects of the isolated compounds on two human tumour cell lines (HEL and MDA-MB-231) were evaluated by the MTT assay. Eighteen compounds showed good inhibitory activities against the HEL cell line, with IC50 values of 3.53–18.7 μM, while nine compounds exhibited moderate cytotoxicity against the MDA-MB-231 cancer cell line, with IC50 values ranging from 4.92 to 10.75 μM. Their preliminary structure-activity relationship of the isolated compounds was also discussed.Graphical abstractNine undescribed compounds and 30 known phenolic compounds were isolated from the whole plants of Hypericum japonicum. 19 compounds showed good inhibitory activities against the HEL and MDA-MB-231 cell lines with IC50 values of 3.53–18.7 μM.Image 1
       
  • Radical coupling reactions of piceatannol and monolignols: A density
           functional theory study
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Thomas Elder, José Carlos del Río, John Ralph, Jorge Rencoret, Hoon Kim, Gregg T. Beckham Recent experimental work has revealed that the hydroxystilbene piceatannol can function as a monomeric unit in the lignification of palm fruit endocarp tissues. Results indicated that piceatannol homo-couples and cross-couples with monolignols through radical reactions and is integrally incorporated into the lignin polymer. The current work reports on the thermodynamics of the proposed reactions using density functional theory calculations. The results indicated that, in general, the energetics of both homo-coupling and cross-coupling are not dissimilar from those of the monolignol coupling, demonstrating the compatibility of piceatannol with the lignification process. Moreover, the DFT methods appear to predict the correct courses of post-coupling rearomatization reactions.Graphical abstractFree energy of dehydrogenation of piceatanol and the unpaired electron density for the resultant free radical.Image 105537
       
  • Selection and validation of appropriate reference genes for real-time
           quantitative PCR analysis in Momordica charantia
    • Abstract: Publication date: August 2019Source: Phytochemistry, Volume 164Author(s): Zhenglong Wang, Jiyang Xu, Yihan Liu, Jiyu Chen, Hanfeng Lin, Yanli Huang, Xiaohong Bian, Yucheng Zhao Real time quantitative reverse transcription PCR (RT-qPCR) has been attracting more attention for its high sensitivity in gene expression analysis. Given the widely use of RT-qPCR in normalization, it is playing a pivotal role for seeking suitable reference genes in different species. In current work, 12 candidate reference genes including Actin 2 (ACT2), Cyclophilin 2 (CYP2), Glyceraldehyde-3-phosphate dehydrogenase C2 (GAPC2), Elongation factor 1-α (EF1-α), Nuclear cap binding protein 20 (NCBP20), Serine/threonine-protein phosphatase PP2A (PP2A), Polypyrimidine tract-binding protein 1 (PTBP1), SAND family protein (SNAD), TIP41-like protein (TIP41), Tubulin beta-6 (TUB6), Ubiquitin-conjugating enzyme 9 (UBC9) and Glyceraldehyde-3-phosphatedehydrogenase (GAPDH) were screened from the transcriptome datasets of M. charantia. Afterwards, GeNorm, NormFinder and BestKeeper algorithms were applied to assess the expression stability of these 12 genes under different abiotic stresses including drought, cold, high-salt, hormone, UV, oxidative and metal stress. The results indicated that 12 selected genes exhibited various stability across the samples under different external stress conditions, but TIP41, PTBP1 and PP2A presented high stability among all the reference genes. To validate the suitability of the identified reference genes, the results of hormone subset were compared with RNA sequencing (RNA-seq) data, and the relative abundance of Ascorbate peroxidase 1(APX1)was used to confirm the reliability of the results. This work assesses the stability of reference genes in M. charantia under different abiotic stress conditions, which will be beneficent for accurate normalization of target genes in M. charantia.Graphical abstractImage 1
       
 
 
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