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  Subjects -> CHEMISTRY (Total: 845 journals)
    - ANALYTICAL CHEMISTRY (47 journals)
    - CHEMISTRY (596 journals)
    - CRYSTALLOGRAPHY (22 journals)
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CHEMISTRY (596 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 5)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 21)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 15)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 22)
ACS Macro Letters     Full-text available via subscription   (Followers: 18)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 31)
ACS Nano     Full-text available via subscription   (Followers: 153)
ACS Photonics     Full-text available via subscription   (Followers: 6)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 16)
Acta Chemica Iasi     Open Access  
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 7)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 4)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 5)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 4)
Advanced Functional Materials     Hybrid Journal   (Followers: 40)
Advanced Science Focus     Free   (Followers: 2)
Advances in Chemical Engineering and Science     Open Access   (Followers: 33)
Advances in Chemical Science     Open Access   (Followers: 10)
Advances in Chemistry     Open Access   (Followers: 7)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 14)
Advances in Drug Research     Full-text available via subscription   (Followers: 21)
Advances in Environmental Chemistry     Open Access   (Followers: 1)
Advances in Enzyme Research     Open Access   (Followers: 4)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 12)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 14)
Advances in Nanoparticles     Open Access   (Followers: 11)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 36)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 13)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 12)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 1)
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 5)
Afrique Science : Revue Internationale des Sciences et Technologie     Open Access   (Followers: 2)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Applied Sciences     Open Access   (Followers: 26)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 69)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 12)
American Journal of Chemistry     Open Access   (Followers: 23)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Full-text available via subscription   (Followers: 7)
Anadolu University Journal of Science and Technology     Open Access  
Analyst     Full-text available via subscription   (Followers: 40)
Angewandte Chemie     Hybrid Journal   (Followers: 107)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 157)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 1)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 2)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 7)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 8)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Full-text available via subscription  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 5)
Applied Spectroscopy     Full-text available via subscription   (Followers: 22)
Applied Surface Science     Hybrid Journal   (Followers: 20)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 4)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 8)
Biochemistry     Full-text available via subscription   (Followers: 196)
Biochemistry Insights     Open Access   (Followers: 4)
Biochemistry Research International     Open Access   (Followers: 4)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 7)
Bioinspired Materials     Open Access   (Followers: 2)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access  
Biomacromolecules     Full-text available via subscription   (Followers: 15)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 9)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 2)
BioNanoScience     Partially Free   (Followers: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 90)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 79)
Bioorganic Chemistry     Hybrid Journal   (Followers: 9)
Biopolymers     Hybrid Journal   (Followers: 16)
Biosensors     Open Access   (Followers: 1)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 3)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 23)
Bulletin of the Korean Chemical Society     Hybrid Journal  
C - Journal of Carbon Research     Open Access   (Followers: 2)
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 3)
Canadian Journal of Chemistry     Full-text available via subscription   (Followers: 6)
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Carbohydrate Research     Hybrid Journal   (Followers: 27)
Carbon     Hybrid Journal   (Followers: 64)
Catalysis for Sustainable Energy     Open Access   (Followers: 4)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 6)
Catalysis Science and Technology     Free   (Followers: 4)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 5)
Cellulose     Hybrid Journal   (Followers: 4)
Central European Journal of Chemistry     Hybrid Journal   (Followers: 6)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription  
ChemCatChem     Hybrid Journal   (Followers: 4)
Chemical and Engineering News     Free   (Followers: 10)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 20)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 15)
Chemical Reviews     Full-text available via subscription   (Followers: 128)
Chemical Science     Open Access   (Followers: 17)
Chemical Technology     Open Access   (Followers: 5)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 4)
Chemical Week     Full-text available via subscription   (Followers: 7)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 53)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 25)
ChemInform     Hybrid Journal   (Followers: 4)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 4)
Chemistry & Biology     Full-text available via subscription   (Followers: 29)
Chemistry & Industry     Hybrid Journal   (Followers: 2)
Chemistry - A European Journal     Hybrid Journal   (Followers: 102)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 11)
Chemistry and Materials Research     Open Access   (Followers: 13)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry Education Research and Practice     Free   (Followers: 4)
Chemistry in Education     Open Access   (Followers: 2)
Chemistry International     Hybrid Journal   (Followers: 1)
Chemistry Letters     Full-text available via subscription   (Followers: 42)
Chemistry of Materials     Full-text available via subscription   (Followers: 134)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 8)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 6)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 3)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 25)
Chromatography     Open Access   (Followers: 5)
Chromatography Research International     Open Access   (Followers: 5)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 8)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 17)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 1)
Composite Interfaces     Hybrid Journal   (Followers: 3)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 10)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 10)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription  
Copernican Letters     Open Access  
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 4)
Crystal Structure Theory and Applications     Open Access   (Followers: 2)
CrystEngComm     Full-text available via subscription   (Followers: 6)
Current Catalysis     Hybrid Journal   (Followers: 1)
Current Metabolomics     Hybrid Journal   (Followers: 3)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 7)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 15)
Current Research in Chemistry     Open Access   (Followers: 7)
Current Science     Open Access   (Followers: 5)
Dalton Transactions     Full-text available via subscription   (Followers: 17)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 1)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 3)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 2)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 4)
Elements     Full-text available via subscription  
Environmental Chemistry     Hybrid Journal   (Followers: 5)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 2)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 3)

        1 2 3 | Last

Journal Cover Carbohydrate Research
  [SJR: 0.654]   [H-I: 83]   [27 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0008-6215 - ISSN (Online) 0008-6215
   Published by Elsevier Homepage  [2970 journals]
  • Synthesis of 6-Phosphofructose Aspartic Acid and Some Related Amadori
           Compounds
    • Abstract: Publication date: Available online 14 May 2016
      Source:Carbohydrate Research
      Author(s): Alexandar L. Hansen, Edward J. Behrman
      We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid.
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       
  • Structure and gene cluster of the O-antigen of Escherichia coli O156
           containing a pyruvic acid acetal
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Zhifeng Duan, Sof'ya N. Senchenkova, Xi Guo, Andrei V. Perepelov, Alexander S. Shashkov, Bin Liu, Yuriy A. Knirel
      The lipopolysaccharide of Escherichia coli O156 was degraded under mild acidic and alkaline conditions and the resulting polysaccharides were studied by sugar analysis and 1H and 13C NMR spectroscopy. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established: where Rpyr indicates R-configurated pyruvic acid acetal. Minor O-acetyl groups also were present and tentatively localized on the Gal residues. The gene cluster for biosynthesis of the O-antigen of E. coli O156 was analyzed and shown to be consistent with the O-polysaccharide structure.
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       
  • Synthesis of the 2-deoxy trisaccharide glycal of antitumor antibiotics
           landomycins A and E
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Xiaohua Li, Justin Woodward, Ali Hourani, Danyang Zhu, Sabrine Ayoub, Jianglong Zhu
      Synthesis of the 2-deoxy trisaccharide glycal of antitumor antibiotics landomycins A and E has been described. The synthesis involves an anomeric O-alkylation for the synthesis of 2-deoxy β-linked disaccharide, a tert-butyldimethylsilyl triflate-catalyzed α-selective L-rhodinosylation, and a lithium 4,4′-di-tert-butylbiphenyl-mediated reductive debenzylation and concomitant reductive lithiation-elimination for the production of the 2-deoxy trisaccharide glycal.
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       
  • Biochemical characterization of the novel α-1,
           3-galactosyltransferase WclR from Escherichia coli O3
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Chao Chen, Bin Liu, Yongchang Xu, Natalia Utkina, Dawei Zhou, Leonid Danilov, Vladimir Torgov, Vladimir Veselovsky, Lu Feng
      Glycosyltransferases (GTs) catalyze the formation of regio- and stereo-specific glycosidic linkages between specific sugar donors and recipients. In this study, the function of the gene wclR from the Escherichia coli O3 O-antigen gene cluster that encodes an α 1, 3-galactosyltransferase (GalT) that acts on the linkage Gal α 1, 3-GlcNAc was biochemically characterized. WclR was expressed in E. coli BL21 (DE3), and the enzymatic product was identified by liquid chromatography-mass spectrometry (LC-MS), collision-induced dissociation electrospray ionization ion trap multiple tandem MS (CID-ESI-IT-MSn) and galactosidase digestion, using UDP-Gal as the donor substrate and the synthetic acceptor substrate GlcNAc-PP-De (decyl diphosphate N-acetylglucosamine). The physiochemical properties and the substrate specificity of WclR were investigated. WclR is the first bacterial GalT characterized that acts on the linkage Gal α 1, 3-GlcNAc. This study enhanced our knowledge of the diversified functions of GTs and provided a novel enzyme source for possible pharmaceutical application.
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       

  •        1,2,3,4,6-Pentakis[-O-(3,4,5-trihydroxybenzoyl)]-α,β-D-glucopyranose
           (PGG) analogs: design, synthesis, anti-tumor and anti-oxidant activities
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Qurat-ul-ain Shaikh, Meiting Yang, Khadim Hussain Memon, Mehreen Lateef, Du Na, Shengbiao Wan, Deslandes Eric, Lijuan Zhang, Tao Jiang
      1,2,3,4,6-Pentakis[-O-(3,4,5-trihydroxybenzoyl)]-α,β-D-glucopyranose (PGG) 12 has been reported for its antioxidant activities, where the free OH groups in PGG seem to be critical for activities. To explore PGG-based compounds as chemotherapeutic agents and to analyze the contribution of specific OH groups in PGG for anti-cancer activities, we designed and synthesized a series of 27 benzoic and cinnamic acid analogs of PGG. These analogs were tested for cytotoxicities against two human lung (A549 and H1299) and two human colon (HCT116 and HT29) cancer cell lines. Compound 12 (PGG) had highest cytotoxicities against HCT116 and A549 cells with IC50 of 1.61 µM and 3.02 µM, respectively. In contrast, the compound 16 (1,2,3,4,6-pentakis[-O-(4-hydroxy-3-methoxybenzoyl)]-α,β-D-glucopyranose, PVG) was most effective at killing HT29 and H1299 cells with IC50 of 1.76 µM and 3.65 µM, respectively, indicating the mutual contribution of m-methoxy and p-hydroxy groups to the observed cytotoxicities. Moreover, cinnamic acid analogs were less active than the benzoic acid analogs evidenced by higher IC50 values. Furthermore, in cinnamic acid analogs the hydrogenation of double bond to saturated 2-C side chain enhance the cytotoxicities in all four cell lines. Compounds also possess good anti-oxidant and reducing activities. Compound 12 and 26 show the highest antioxidant and reducing activities.
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       
  • Efficient chemoenzymatic synthesis of 4-nitrophenyl
           β-d-apiofuranoside and its use in screening of
           β-d-apiofuranosidases
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Peter Kis, Elena Potocká, Vladimír Mastihuba, Mária Mastihubová
      4-Nitrophenyl β-d-apiofuranoside as a chromogenic probe for detection of β-d-apiofuranosidase activity was prepared in 61% yield from 2,3-isopropylidene-α,β-d-apiofuranose through a sequence of five reactions. The synthesis involves one regioselective enzymatic step—benzoylation of primary hydroxyl of 2,3-isopropylidene-α,β-d-apiofuranose catalysed by Lipolase 100T and stereoselective β-d-apiofuranosylation of p-nitrophenol using BF3⋅OEt2/Et3N. The product was used for screening of β-d-apiofuranosidase activity in 61 samples of crude commercial enzymes and plant materials. Fifteen enzyme preparations originating from different strains of genera Aspergillus display β-d-apiofuranosidase activity. The highest activity was found in Rapidase AR 2000 (78.27 U/g) and lyophilized Viscozyme L (64,36 U/g).
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       
  • A β-agarase with high pH stability from Flammeovirga sp. SJP92
    • Abstract: Publication date: Available online 14 May 2016
      Source:Carbohydrate Research
      Author(s): Qi Dong, Lingwei Ruan, Hong Shi
      A novel endo-type β-agarase, AgaB, was cloned from an agar-degrading bacterium, Flammeovirga sp. SJP92. The gene agaB consists of 2, 550 bp and encodes a protein of 849 amino acids including a 19 amino acids signal peptide. Based on the amino acid sequence similarity, AgaB belongs to the glycoside hydrolase family GH16. The recombinant AgaB was expressed in Escherichia coli and exhibited maximal activity at around 45°C and pH 8.0, with a specific activity of 254.2 U/mg, a K m of 3.99 mg/ml and a V max of 700 U/mg for agarose. The agarase was stable at neutral to mildly alkaline condition, and remained 85%-90% of activity after treatment for 1 h, a characteristic much more different from other agarases reported. The recombinant enzyme was sensitive to some metal ions (Cu2+, Co2+ and Zn2+), but resistant to some denaturants (urea and SDS). It can hydrolyze the β-1, 4-glycosidic linkages of agarose, yielding neoagarotetraose and neoagarohexaose as the main products. These properties could make AgaB has a potential application in the food, cosmetic and medical industries.
      Graphical abstract image

      PubDate: 2016-05-17T10:15:12Z
       
  • Structural determination of the polysaccharide isolated from biofilms
           produced by a clinical strain of klebsiella pneumoniae
    • Abstract: Publication date: Available online 5 May 2016
      Source:Carbohydrate Research
      Author(s): Paola Cescutti, Gianluigi De Benedetto, Roberto Rizzo
      Klebsiella pneumoniae are Gram negative opportunistic pathogens producing capsular (K) polysaccharides. Seventy seven different K antigens have been described and they are the basis for K serotyping. Capsular polysaccharides are important virulence factors and have a relevant role for the structure of biofilm communities. Nevertheless, little information is available on the polysaccharides produced in biofilm matrices by Klebsiella spp. In the present study, a clinical isolate of Klebsiella pneumoniae was grown both on cellulose membranes deposited on agar plates, where it formed an adherent biofilm, and in liquid medium, where it formed floating biofilms (flocs). Extraction and purification of the polysaccharide fraction showed that only one main carbohydrate polymer was present in both adherent biofilms and flocs. Composition and linkage analysis, Smith degradation followed by ESI-MS, 1D and 2D NMR spectroscopy revealed that the polysaccharide belong to the type K24 and has the following structure:
      Graphical abstract image

      PubDate: 2016-05-07T07:00:11Z
       
  • Binding activities of non-β-glucan glycoclusters to dectin-1 and
           exploration of their binding site
    • Abstract: Publication date: Available online 6 May 2016
      Source:Carbohydrate Research
      Author(s): Shan Jiang, Shan Niu, Wang Yao, Zhong-Jun Li, Qing Li
      Dectin-1, which specifically recognizes β-(1,3)-glucans, plays an important role in innate immune responses. For the first time, in this study we found that a series of non-β-glucan glycoclusters can bind to dectin-1 by means of surface plasmon resonance (SPR) assay. Hexavalent lactosides Ju-6 showed strongest affinity property (K D=1.6 µM). Interestingly, a continuous binding-dissociation experiment on SPR showed that Ju-6 and Laminarin binding to dectin-1 are independent of each other. Moreover, RT-PCR assay showed that Ju-6 cannot up-regulate cytokine gene expression, or inhibit the promoting effect caused by Zymosan (a long-chain β-glucan). These results indicated that there might be a possible new carbohydrate binding site on dectin-1.
      Graphical abstract image

      PubDate: 2016-05-07T07:00:11Z
       
  • Facile synthesis of aminooxy glycosides by gold(III)-catalyzed
           glycosidation
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Shivaji A. Thadke, Mahesh Neralkar, Srinivas Hotha
      The O-glycosidation of hydroxysuccinimides and hydroxyphthalimides with a variety of aldose derived propargyl 1,2-orthoesters under the gold(III)-catalyzed glycosidation conditions is reported. A wide range of hydroxysuccinimidyl and hydroxyphthalimidyl glycosides were synthesized from corresponding glycosyl orthoesters including glucosyl, mannosyl, galactosyl, ribofuranosyl, arabinofuranosyl, lyxofuranosyl and xylofuranosyl using gold catalysis repertoire. The protocol is identified to be compatible for the synthesis of aminooxy glycosides of higher oligosaccharides as well.
      Graphical abstract image

      PubDate: 2016-05-07T07:00:11Z
       
  • Automated fluorous-assisted solution-phase synthesis of β-1,2-, 1,3-,
           and 1,6-mannan oligomers
    • Abstract: Publication date: 22 July 2016
      Source:Carbohydrate Research, Volume 430
      Author(s): Shu-Lun Tang, Nicola L.B. Pohl
      Automated solution-phase syntheses of β-1,2-, 1,3-, and 1,6-mannan oligomers have been accomplished by applying a β-directing C-5 carboxylate strategy. Fluorous-tag-assisted purification after each reaction cycle allowed the synthesis of short β-mannan oligomers with limited loading of glycosyl donor—as low as 3.0 equivalents for each glycosylation cycle. This study showed the capability of the automated solution-phase synthesis protocol for synthesizing various challenging glycosides, including use of a C-5 ester as a protecting group that could be converted under reductive conditions to a hydroxymethyl group for chain extension.
      Graphical abstract image

      PubDate: 2016-05-07T07:00:11Z
       
  • Block synthesis of A (type 2) and B (type 2) tetrasaccharides related to
           the human ABO blood group system
    • Abstract: Publication date: Available online 4 May 2016
      Source:Carbohydrate Research
      Author(s): Ivan M. Ryzhov, Elena Yu. Korchagina, Inna S. Popova, Tatiana V. Tyrtysh, Alexander S. Paramonov, Nicolai V. Bovin
      Herein we report the synthesis of 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides via [3+1] block scheme. Peracetylated trichloroacetimidates of A and B trisaccharides were used as glycosyl donors. The well-known low reactivity of 4-OH group of N-acetyl-d-glucosamine forced us to test four glucosamine derivatives (3-Bz-1,6-anhydro-GlcNAc, and 3-trifluoroacetamidopropyl β-glycosydes of 3-Ac-6-Bn-GlcNAc, 3-Ac-6-Bn-GlcN3, and 3-Ac-6-Bn-GlcNAc2) to select the best glycosyl acceptor for the synthesis of type 2 tetrasaccharides. The desired tetrasacchrides were not isolated, when 3-trifluoroacetamidopropyl glycosyde of 3-Ac-6-Bn-GlcNAcβ was glycosylated. Glycosylation of 3-Bz-1,6-anhydro-GlcNAc derivative resulted in α-glycoside as a major product. High stereospecificity was achieved only in the synthesis of B (type 2) tetrasaccharide, when 3-trifluoroacetamidopropyl 3-Ac-6-Bn-GlcNAc2β was applied as the glycosyl acceptor (β/α 5:1), whereas glycosylation with trichloroacetimidate of A trisaccharide was not stereospecific (β/α 1.3:1). Glycosylation of 3-trifluoroacetamidopropyl glycosyde of 3-Ac-6-Bn-GlcN3β with trichloroacetimidates of A and B trisaccharides provided the same stereochemical yield (β/α 1.5:1).
      Graphical abstract image

      PubDate: 2016-05-05T06:55:12Z
       
  • Structural characterization of the lipoteichoic acid isolated from
           staphylococcus sciuri w620
    • Abstract: Publication date: Available online 4 May 2016
      Source:Carbohydrate Research
      Author(s): Katarzyna A. Duda, Sandra Petersen, Otto Holst
      Lipoteichoic acid (LTA) is an important cell envelope compound of Gram-positive bacteria. LTA isolated from allergy-protective Staphylococcus sciuri W620 strain was characterized by chemical analyses as well as 1D and 2D NMR experiments. Compositional analyses indicated the presence of glycerol (Gro), phosphate-Gro, alanine-Gro, glucose (Glc) and fatty acids. The studied strain produced LTA with backbone composed of glycerol-phosphate repeating units only substituted with d-alanine (Ala) and the lipid anchor, typically for genus Staphyloccocus, possessing the structure β-d-Glcp(1→6)- β-d-Glcp(1→3)-1,2-diacyl-sn-Gro.
      Graphical abstract image

      PubDate: 2016-05-05T06:55:12Z
       
  • Structure and gene cluster of the O-antigen of Enterobacter cloacae G3421
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427
      Author(s): Andrei V. Perepelov, Andrei V. Filatov, Min Wang, Alexander S. Shashkov, Lei Wang, Yuriy A. Knirel
      The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3421 and studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy. In addition, partial solvolysis with anhydrous trifluoroacetic acid was applied, which cleaved selectively the α-l-rhamnopyranosidic linkages. The following structure of the branched hexasaccharide repeating unit was established. The O-polysaccharide studied shares the β-l-Rhap-(1→4)-α-l-Rhap-(1→2)-α-l-Rhap trisaccharide fragment with the O-polysaccharide of Shigella boydii type 18. The O-antigen gene cluster of E. cloacae G3421 was sequenced. Functions of genes in the cluster, including those for glycosyltransferases, were tentatively assigned by a comparison with sequences in the available databases and found to be consistent with the O-polysaccharide structure.
      Graphical abstract image

      PubDate: 2016-05-05T06:55:12Z
       
  • Complete NMR assignment of a bisecting hybrid-type oligosaccharide
           transferred by Mucor hiemalis endo-β-N-acetylglucosaminidase
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427
      Author(s): Takashi Yamanoi, Yoshiki Oda, Kaname Katsuraya, Toshiyuki Inazu, Kenji Yamamoto
      This study describes the complete nuclear magnetic resonance (NMR) spectral assignment of a bisecting hybrid-type oligosaccharide 1, transferred by Mucor hiemalis endo-β-N-acetylglucosaminidase (Endo-M). Through 1H- and 13C-NMR, DQF-COSY, HSQC, HMBC, TOCSY, and NOESY experiments, we determine the structure of the glycoside linkage formed by the Endo-M transglycosylation, i.e., the connection between GlcNAc and GlcNAc in oligosaccharide 1.
      Graphical abstract image

      PubDate: 2016-05-05T06:55:12Z
       
  • Editorial board
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427




      PubDate: 2016-05-05T06:55:12Z
       
  • Graphical contents list
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427




      PubDate: 2016-05-05T06:55:12Z
       
  • Structure–reactivity relationship of Amadori rearrangement products
           compared to related ketoses
    • Abstract: Publication date: 16 June 2016
      Source:Carbohydrate Research, Volume 428
      Author(s): Martin Kaufmann, Philipp M. Meissner, Daniel Pelke, Clemens Mügge, Lothar W. Kroh
      Structure-reactivity relationships of Amadori rearrangement products compared to their related ketoses were derived from multiple NMR spectroscopic techniques. Besides structure elucidation of six Amadori rearrangement products derived from d-glucose and d-galactose with l-alanine, l-phenylalanine and l-proline, especially quantitative 13C selective saturation transfer NMR spectroscopy was applied to deduce information on isomeric systems. It could be shown exemplarily that the Amadori compound N-(1-deoxy-d-fructos-1-yl)-l-proline exhibits much higher isomerisation rates than d-fructose, which can be explained by C-1 substituent mediated intramolecular catalysis. In combination with a reduced carbonyl activity of Amadori compounds compared to their related ketoses which results in an increased acyclic keto isomer concentration, the results on isomerisation dynamics lead to a highly significant increased reactivity of Amadori compounds. This can be clearly seen, comparing approximated carbohydrate milieu stability time constants (ACuSTiC) which is 1 s for N-(1-deoxy-d-fructos-1-yl)-l-proline and 10 s for d-fructose at pD 4.20 ± 0.05 at 350 K. In addition, first NMR spectroscopic data are provided, which prove that α-pyranose of (amino acid substituted) d-fructose adopts both, 2C5 and 5C2 conformation.
      Graphical abstract image

      PubDate: 2016-05-05T06:55:12Z
       
  • Synthesis of modified D-mannose core derivatives and their impact on GH38
           α-mannosidases
    • Abstract: Publication date: 16 June 2016
      Source:Carbohydrate Research, Volume 428
      Author(s): Monika Poláková, Radim Horák, Sergej Šesták, Ivana Holková
      Nine new compounds having five- and modified six-member carbohydrate core derived from D-lyxose or D-mannose, and non-hydrolysable aglycones (benzylsulfonyl or aryl(alkyl)triazolyl) were synthesised to investigate their ability to inhibit the recombinant Drosophila melanogaster homologs of two human GH38 family enzymes: Golgi mannosidase II (dGMIIb) and lysosomal mannosidase (dLMII). Two compounds were weak selective dGMIIb inhibitors showing IC50 at mM level. Moreover, it was found that another GH38 enzyme, commercial jack bean α-mannosidase, was inhibited by triazole conjugates regardless of the carbohydrate core while the corresponding sulfones were inactive.
      Graphical abstract image

      PubDate: 2016-05-05T06:55:12Z
       
  • Modified polysaccharides as potential 19f magnetic resonance contrast
           agents
    • Abstract: Publication date: Available online 19 April 2016
      Source:Carbohydrate Research
      Author(s): Tomasz Krawczyk, Masafumi Minoshima, Fuminori Sugihara, Kazuya Kikuchi
      The introduction of 3-aminobenzotrifluoride into partially oxidized alginic acid, dextran, and polygalacturonic acid (10-100 kDa) by means of the imine formation and a subsequent reduction resulted in water-soluble materials containing 1-14% of fluorine. They showed a single or split 19F NMR signal in a narrow range of -63 to -63.5 ppm. The observed T 1 and T 2 were approximately 1 and 0.2 s at 400 or 500 MHz instruments, respectively. The samples showed low toxicity and uptake towards the HeLa cells similar to native polysaccharides and were preferentially localized in lysosomes. A tail intravenous injection of 5 mg of modified dextran containing 1% of fluorine revealed that the probe was not trapped in liver, spleen or kidneys, but was quickly cleared with urine. The proposed materials can be used for imaging of the gastrointestinal tract or the genitourinary system and act as a material for more complex 19F MRI agent synthesis.
      Graphical abstract image

      PubDate: 2016-04-22T11:49:55Z
       
  • Preparation of chitooligosaccharides from fungal waste mycelium by
           recombinant chitinase
    • Abstract: Publication date: Available online 19 April 2016
      Source:Carbohydrate Research
      Author(s): Mengyuan Lv, Ying Hu, Michael G. Gänzle, Jianguo Lin, Changgao Wang, Jun Cai
      This study aimed to develop an enzymatic method for conversion of chitin from fungal waste mycelia to chitooligosaccharides. The recombinant chitinase LlChi18A from Lactococcus lactis was over-expressed by Escherichia coli BL21 (DE3) and purified by affinity chromatography. The enzymatic properties of the purified enzyme were studied by chitin oligosaccharides. Waste mycelium was pre-treated by alkaline. The optimal conditions for hydrolysis of fungal chitin by recombinant chitinase were determined by Shales method. HPLC/ESI-MS was used to determine the content of N-acetylglucosamine and chitooligosaccharides after hydrolysis. The level of reducing sugar released from pretreated mycelium by chitinase increased with the reaction time during 6 days. The main product in the hydrolysates was N,N'-diacetylchitobiose. After hydrolysis by chitinase for 5 d, the yield of N,N'-diacetylchitobiose from waste mycelium was around 10% with estimated purity around 70%. Combination of chitinase and snailase remarkably increased the yield to 24% with purity of 78%. Fungal mycelium which contains chitin is a new potential source for obtaining food grade chitooligosaccharides.
      Graphical abstract image

      PubDate: 2016-04-22T11:49:55Z
       
  • Stimulus-responsiveness and methyl violet release behaviors of
           poly(NIPAAm-co-AA) hydrogels chemically crosslinked with
           β-cyclodextrin polymer bearing methacrylates
    • Abstract: Publication date: Available online 19 April 2016
      Source:Carbohydrate Research
      Author(s): Hui Zhao, Jun Gao, Ruina Liu, Sanping Zhao
      To fabricate thermo- and pH-sensitive hydrogels functionalized with β-cyclodextrin (β-CD) moieties, β-CD polymer bearing methacrylate (CDP-g-GMA) using as a reactive and functional crosslinker was synthesized, and then copolymerized with N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) in aqueous solution via UV-initiated free radical polymerization. The stimulus-responsiveness of the resultant hydrogels has been carried out by measuring the swelling ratio at different temperatures and pH values. The results showed that the thermo- and pH-sensitivities of the produced hydrogels were significantly dependent on the compositions of the hydrogels, and the dual sensitivities exhibited good reversible process. The interior morphology observed by SEM exhibited that the pore size of the hydrogels could be tailored by pH of the local medium. Using a water-soluble cationic dye Methyl Violet (MV) as a model drug, MV loading and release profiles of the hydrogels as potential drug controlled release carriers were evaluated. The MV release rate from CD-functionalized hydrogels was much slower than that from the hydrogel without β-CDs at both pH 2.0 and pH 7.4. The release of MV from CD-functionalized hydrogels at pH 2.0 was faster than that at pH 7.4, the release kinetics of MV from the CD-functionalized hydrogels displayed a sustained release profile, and the release mechanism followed Fickian diffusion.
      Graphical abstract image

      PubDate: 2016-04-22T11:49:55Z
       
  • Structure of the O-polysaccharide of Escherichia coli O132
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427
      Author(s): Alexander S. Shashkov, Wenwen Zhang, Andrei V. Perepelov, Andrej Weintraub, Bin Liu, Göran Widmalm, Yuriy A. Knirel
      Mild acid degradation of the lipopolysaccharide of Escherichia coli O132 released its O-polysaccharide. Analysis by 1D and 2D 1H and 13C NMR spectroscopy prior and subsequent to O-deacetylation, in conjunction with sugar analysis, revealed a linear pentasaccharide repeating unit of the O-polysaccharide having the following structure: →2)-α-d-Galf-(1→3)-α-l-Rhap2Ac-(1→4)-α-d-Glcp-(1→2)-α-l-Rhap-(1→3)-β-d-GlcpNAc-(1→ Putative functions of genes in the O-antigen gene cluster of E. coli O132 are consistent with the O-polysaccharide structure.
      Graphical abstract image

      PubDate: 2016-04-22T11:49:55Z
       
  • A study of the metal binding capacity of saccharinic acids formed during
           the alkali catalysed decomposition of cellulosic materials: nickel
           complexation by glucoisosaccharinic acids and xyloisosaccharinic acids
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427
      Author(s): Michael Almond, Daniel Belton, Paul N. Humphreys, Andrew P. Laws
      The stoichiometry of the metal complexes formed between nickel and the ligand β-glucoisosaccharinic acid (β-GISA) and a racemic mixture of enantiomers of xyloisosaccharinic acid (XISA) has been determined at both neutral and alkaline pHs. Bjerrum plots, Job's plots and conductance measurements indicated that for each of the systems one to one Ni(ligand) complexes were formed at near neutral pHs (<7.5). At intermediate alkaline pHs (7.5–13) there is evidence to support the formation and precipitation of Ni2(ligand)(OH)3 complexes, finally, at high pH (>13) sparingly soluble Ni2(ligand)(OH)4 complexes were formed. The stability constants for the Ni(β-GISA), Ni(α-GISA) and Ni(XISA) complexes formed at neutral pH were determined under identical conditions using polarographic studies. The measured stability constants for Ni(β-GISA) (log10 β = 1.94 ± 0.15) and for Ni(α-GISA)(log10 β = 2.07 ± 0.13) are very similar; the value measured for the Ni(XISA) complex (log10 β = 0.83) was an order of magnitude smaller. The stability constants for the Ni2(Ligand)(OH)4 complexes formed at highly alkaline pHs were determined using the Schubert method. The measured stability constant for Ni2(β-GISA)(OH)4 (log10 β = 30.6 ± 0.5) was an order of magnitude bigger than the value for Ni2(α-GISA)(OH)4 (log10 β = 29.0 ± 0.5) measured under identical conditions. Attempts to measure the stability constant for Ni2(XISA)(OH)4 were unsuccessful; Ni2(XISA)(OH)4 complexes were not present in significant amounts at high pH to allow the log10β value to be determined by the Schubert method.
      Graphical abstract image

      PubDate: 2016-04-22T11:49:55Z
       
  • The structure of the lipooligosaccharide from Xanthomonas oryzae pv.
           Oryzae: the causal agent of the bacterial leaf blight in rice
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427
      Author(s): Flaviana Di Lorenzo, Angelo Palmigiano, Alba Silipo, Yoshitake Desaki, Domenico Garozzo, Rosa Lanzetta, Naoto Shibuya, Antonio Molinaro
      The structure of the lipooligosaccharide (LOS) from the rice pathogen Xanthomonas oryzae pv. oryzae has been elucidated. The characterization of the core oligosaccharide structure was obtained by the employment of two chemical degradation protocols and by analysis of the products via NMR spectroscopy. The structure of the lipid A portion was achieved by MALDI mass spectrometry analysis on purified lipid A. The LOS from Xanthomonas oryzae pv. oryzae revealed to possess the same core structure of Xanthomonas campestris pv. campestris and interesting novel features on its lipid A domain. The evaluation of the biological activity of both LOS and isolated lipid A was also executed.
      Graphical abstract image

      PubDate: 2016-04-18T14:11:24Z
       
  • Fractionation and analysis of lipopolysaccharide-derived oligosaccharides
           by zwitterionic-type hydrophilic interaction liquid chromatography coupled
           with electrospray ionisation mass spectrometry
    • Abstract: Publication date: 2 June 2016
      Source:Carbohydrate Research, Volume 427
      Author(s): Aleksandra Man-Kupisinska, Ewelina Bobko, Tomasz K. Gozdziewicz, Anna Maciejewska, Wojciech Jachymek, Czeslaw Lugowski, Jolanta Lukasiewicz
      Lipopolysaccharide (LPS, endotoxin) is a main surface antigen and virulence factor of Gram-negative bacteria. Regardless of the source of LPS, this molecule, isolated from the smooth forms of bacteria, is characterised by a general structural layout encompassing three regions: (i) an O-specific polysaccharide (O-PS) – a polymer of repeating oligosaccharide units, (ii) core oligosaccharide (OS), and (iii) the lipid A anchoring LPS in the outer membrane of the cell envelope of Gram-negative bacteria. Structural analysis usually requires degradation of LPS and further efficient separation of various poly- and oligosaccharide glycoforms. The hydrophilic interaction liquid chromatography (HILIC) was shown as an efficient technique for separation of labelled or native neutral and acidic glycans, glycopeptides, sialylated glycans, glycosylated and nonglycosylated peptides. Herein we adopted ZIC® (zwitterionic stationary phase covalently attached to porous silica)-HILIC technology in combination with electrospray ionisation mass spectrometry to separate different LPS-derived oligosaccharides. As a result three effective procedures have been developed: (i) to separate different core oligosaccharides of Escherichia coli R1 LOS, (ii) to separate RU-[Hep]-Kdo oligosaccharides from core OS glycoforms of Hafnia alvei PCM 1200 LPS, and (iii) to separate Hep and Kdo-containing mono, di-, tri- and tetrasaccharides of H. alvei PCM 1200 LPS. Moreover, some of developed analytical procedures were scaled to semi-preparative protocols and used to obtain highly-purified fractions of the interest in larger quantities required for future evaluation, analysis, and biological applications.
      Graphical abstract image

      PubDate: 2016-04-18T14:11:24Z
       
  • Branching of hemicelluloses through an azetidinium salt ring-opening
           reaction
    • Abstract: Publication date: Available online 11 April 2016
      Source:Carbohydrate Research
      Author(s): Mikaela Börjesson, Gunnar Westman
      During the last century there has been a steady increase in the number of publications on practical applications of hemicellulose. Due to the water and moisture sensitivity, poor film-forming ability and lack of thermal processability most of the hemicelluloses needs to be chemically modified prior to processed into materials. Within this study we present the results of azetidinium salts as a new functional group for conjugation to polysaccharides. The reactivity of three azetidinium salts on xylan, arabinoxylan and galactoglucomannan was investigated. Carbonyl groups were found to be favorable for the reaction with azetidinium salts and thus the glucuronic acids content in the hemicellulose determines the degree of substitution. TEMPO-oxidation of the hemicelluloses was done which successfully increased the degree of substitution. The highly reactive azetidinium salts are easily synthesized from secondary amines and epichlorohydrin and can be used as a new tool towards functionalization of hemicelluloses into the after sought properties.
      Graphical abstract image

      PubDate: 2016-04-14T06:31:47Z
       
  • Effect of a single point mutation on the interaction of glucans with a
           glucansucrase from leuconostoc mesenteroides NRRL b-1118
    • Abstract: Publication date: Available online 12 April 2016
      Source:Carbohydrate Research
      Author(s): Gregory L. Côté, Christopher D. Skory
      Our previous work showed that substitution of an amino acid that is coupled with the +2 subsite adjacent to the transition stabilizer of a glucansucrase, which produces a water-insoluble glucan, resulted in significant changes in the structures and yields of the water-insoluble glucans produced. We now describe how these changes affect the ability of the glucansucrase to bind to exogenous glucans, and how these glucans can influence the yield, product structures, and kinetics of the mutant glucansucrases. The activity of the wild-type enzyme, with threonine at position 654, is not significantly activated by added dextran, and the yield of water-insoluble glucan from sucrose is only slightly increased by dextran. Mutant T654Y is not affected at all by the addition of dextran. However, several mutant enzymes exhibit markedly lower yields of glucan relative to the wild type; these lower yields can be partially or completely overcome by the addition of water-soluble dextran. Although evidence indicates that the soluble dextran is incorporated into water-insoluble glucan, the increased yields cannot be accounted for solely by incorporation of the dextran into insoluble product. Furthermore, these DsrI mutants are significantly activated by exogenous glucans. The addition of dextran does not markedly change the KM for sucrose in the mutant enzymes, but does increase the Vmax of the reaction. These effects apparently depend on the presence of unbranched sequences of α1→6-linked D-glucose units in the glucan.
      Graphical abstract image

      PubDate: 2016-04-14T06:31:47Z
       
  • Dynamics simulation of soybean agglutinin (SBA) dimer reveals the impact
           of glycosylation on its enhanced structural stability
    • Abstract: Publication date: Available online 12 April 2016
      Source:Carbohydrate Research
      Author(s): Swagata Halder, Avadhesha Surolia, Chaitali Mukhopadhyay
      The legume lectins are widely used as a model system for studying protein-carbohydrate and protein-protein interactions. They exhibit a fascinating quaternary structure variation. Recently, it has become clear that lectins exist as oligomers. Soybean agglutinin is a tetrameric legume lectin, each of whose subunits are glycosylated. In the present study we explore the main origin for the stability of soybean agglutinin dimer. In order to understand the role of glycosylation on the dimeric interface, we have carried out normal (298K), high temperatures (380K, 500K) long explicit solvent molecular dynamics (MD) simulations and compared the structural and conformational changes between the glycosylated and non-glycosylated dimers. The study reveals that the high degree of stability at normal temperature is mostly contributed by interfacial ionic interactions (~200 kcal/mol) between polar residues like Lys, Arg, Asp, Thr, Ser, Asn and Gln (62%). It maintains its overall folded conformation due to high subunit interactions at the noncanonical interface. Mainly five important hydrogen bonds between C=O of one β sheet of one subunit with the N-H of other β strand of the other subunit help to maintain the structural integrity. Ten inter subunit salt-bridge interactions between Arg 185- Asp'192, Lys163–Asp'169, Asp 169-Lys' 163 and Asp 192- Arg' 185 at noncanonical interface appear to be important to maintain the three dimensional structure of SBA dimer. Moreover, our simulation results revealed that increase in vibrational entropy could decrease the free energy and contribute to the glycan-induced stabilization by ~45kcal /mol at normal temperature.
      Graphical abstract image

      PubDate: 2016-04-14T06:31:47Z
       
  • Formation of isomers of anionic hemiesters of sugars and carbonic acid in
           aqueous medium
    • Abstract: Publication date: Available online 12 April 2016
      Source:Carbohydrate Research
      Author(s): Vagner Bezerra dos Santos, Denis Tadeu Rajh Vidal, Kelliton José Mendonça Francisco, Lucas Colucci Ducati, Claudimir Lucio do Lago
      Hemiesters of carbonic acid can be freely formed in aqueous media containing HCO3 -/CO2 and mono- or poly-hydroxy compounds. Herein, 13C NMR spectroscopy was used to identify isomers formed in aqueous solutions of glycerol (a prototype compound) and seven carbohydrates, as well as to estimate the equilibrium constant of formation (Keq ). Although both isomers are formed, glycerol 1-carbonate corresponds to 90% of the product. While fructose and ribose form an indistinct mixture of isomers, the anomers of d-glucopyranose 6-carbonate correspond to 74% of the eight isomers of glucose carbonate that were detected. The values of Keq for the disaccharides sucrose (4.3) and maltose (4.2) are about twice the values for the monosaccharides glucose (2.0) and fructose (2.3). Ribose (Keq = 0.89) – the only sugar without a significant concentration of a species containing a -CH2OH group in an aqueous solution – resulted in the smallest Keq . On the basis of the Keq value and the concentrations of HCO3 - and glucose in blood, one can anticipate a concentration of 2 – 4 µmol L–1 for glucose 6-carbonate, which corresponds to ca. of 10% of the its phosphate counterpart (glucose 6-phosphate).
      Graphical abstract image

      PubDate: 2016-04-14T06:31:47Z
       
  • FTIR, HATR and FT-raman studies on the anhydrous and monohydrate species
           of maltose in aqueous solution
    • Abstract: Publication date: Available online 12 April 2016
      Source:Carbohydrate Research
      Author(s): Maximiliano A. Iramain, Lilian Davies, Silvia A. Brandán
      The structures of α- and β-maltose anhydrous and their corresponding monohydrated species were studied combining the FT-IR, FT-Raman and HATR spectra with DFT calculations. The four structures were optimized in gas and aqueous solution by using the hybrid B3LYP/6-31G* method. The self-consistent force field (SCRF) calculations together with the polarized continuum (PCM) model were used to study the systems in solution while the solvation energies were computed using the solvation model (SM). The calculated structural and vibrational properties could explain the anomerization of maltose in solution, as was reported in the literature while the natural bond orbital (NBO) analyses for those species support clearly the mutarotation equilibria between both forms in solution, evidencing the anhydrous forms the equilibrium: α (45%) ⇔ β (55%), similar to that experimentally reported at 20 °C. Bands of all the species observed in the vibrational spectra support the presence of the anomeric species of maltose in solution while the presence of dimeric species justify the intense IR bands observed in the higher wavenumbers region. The similar gap values for maltose and lactose probably justify that these sugars are reducing sugars while the high values in sucrose could explain that it is a non-reducing sugar. On the other hand, the sweeteners cyclamate and sacarine are most reactive in solution than the sugars maltose, lactose and sucrose, as expected due to their ionic characteristics. The predicted vibrational spectra for the four species of maltose show reasonable concordances with the corresponding experimental ones. The f(δC-O-C) force constants of the glycosidic bonds follow the tendency: maltose > lactose > sucrose.
      Graphical abstract image

      PubDate: 2016-04-14T06:31:47Z
       
  • Graphical contents list
    • Abstract: Publication date: 13 May 2016
      Source:Carbohydrate Research, Volume 426




      PubDate: 2016-04-14T06:31:47Z
       
  • Corrigendum to “In vitro single-vessel enzymatic synthesis of novel
           resvera-A glucosides” [Carbohydr. Res. 424 (2016) 8–14]
    • Abstract: Publication date: 13 May 2016
      Source:Carbohydrate Research, Volume 426
      Author(s): Ju Yong Shin, Ramesh Prasad Pandey, Ha Young Jung, Luan Luong Chu, Yong Il Park, Jae Kyung Sohng



      PubDate: 2016-04-14T06:31:47Z
       
  • Editorial board
    • Abstract: Publication date: 13 May 2016
      Source:Carbohydrate Research, Volume 426




      PubDate: 2016-04-14T06:31:47Z
       
  • “Coding” and “decoding”: hypothesis for the
           regulatory mechanism involved in heparan sulfate biosynthesis
    • Abstract: Publication date: Available online 8 April 2016
      Source:Carbohydrate Research
      Author(s): Xu Zhang, Fengshan Wang, Juzheng Sheng
      Heparan sulfate (HS) is widely distributed in mammalian tissues in the form of HS proteoglycans, which play essential roles in various physiological and pathological processes. In contrast to the template-guided processes involved in the synthesis of DNA and proteins, HS biosynthesis is not believed to involve a template. However, it appears that the final structure of HS chains was strictly regulated. Herein, we report research based hypothesis that two major steps, namely “coding” and “decoding” steps, are involved in the biosynthesis of HS, which strictly regulate its chemical structure and biological activity. The “coding” process in this context is based on the distribution of sulfate moieties on the amino groups of the glucosamine residues in the HS chains. The sulfation of these amine groups is catalyzed by N-deacetylase/N-sulfotransferase, which has four isozymes. The composition and distribution of sulfate groups and iduronic acid residues on the glycan chains of HS are determined by several other modification enzymes, which can recognize these coding sequences (i.e., the “decoding” process). The degree and pattern of the sulfation and epimerization in the HS chains determines the extent of their interactions with several different protein factors, which further influences their biological activity.
      Graphical abstract image

      PubDate: 2016-04-08T18:10:51Z
       
  • Glycan specificity of neuraminidases determined in microarray format
    • Abstract: Publication date: Available online 8 April 2016
      Source:Carbohydrate Research
      Author(s): Janet E. McCombs, Jason Diaz, Kevin J. Luebke, Jennifer J. Kohler
      Neuraminidases hydrolytically remove sialic acids from glycoconjugates. Neuraminidases are produced by both humans and their pathogens, and function in normal physiology and in pathological events. Identification of neuraminidase substrates is needed to reveal their mechanism of action, but high-throughput methods to determine glycan specificity of neuraminidases do not exist. Here we use two glycan labeling reactions to monitor neuraminidase activity toward glycan substrates. While both periodate oxidation and aniline-catalyzed oxime ligation (PAL) and galactose oxidase and aniline-catalyzed oxime ligation (GAL) can be used to monitor neuraminidase activity toward glycans in microtiter plates, only GAL accurately measured neuraminidase activity toward glycans displayed on a commercial glass slide microarray. Using GAL, we confirm known linkage specificities of three pneumococcal neuraminidases and obtain new information about underlying glycan specificity.
      Graphical abstract image

      PubDate: 2016-04-08T18:10:51Z
       
  • Structure of the o-specific polysaccharide from the marine bacterium
           rheinheimera japonica KMM 9513t, containing n-glycosidic bond between
           monosaccharides.
    • Abstract: Publication date: Available online 6 April 2016
      Source:Carbohydrate Research
      Author(s): Maxim S. Kokoulin, Anatoly I. Kalinovskiy, Svetlana V. Tomshich, Lyudmila A. Romanenko, Valery V. Mikhailov, Nadezhda A. Komandrova
      The O-specific polysaccharide was isolated from the lipopolysaccharide of type strain Rheinheimera japonica KMM 9513T and studied by sugar analysis, Smith degradation, and two-dimensional 1H and 13C NMR spectroscopy including 1H,1H-TOCSY, 1H,1H-COSY, 1H,1H-ROESY, 1H,13C-HSQC, 1H,13C-HMBC, 1H,13C-H2BC and 1H,13C-HSQC-TOCSY experiments. The new structure of the O-specific polysaccharide of R. japonica KMM 9513T containing N-glycosidic bond was established:
      Graphical abstract image

      PubDate: 2016-04-08T18:10:51Z
       
  • Further studies on cation clock reactions in glycosylation: observation of
           a configuration specific intramolecular sulfenyl transfer and isolation
           and characterization of a tricyclic acetal
    • Abstract: Publication date: Available online 6 April 2016
      Source:Carbohydrate Research
      Author(s): Min Huang, Takayuki Furukawa, Pascal Retailleau, David Crich, Luis Bohé
      The use of the 2-O-(2-trimethylsilylmethallyl) group as intramolecular nucleophile and cation clock reaction in the glucopyranose series depends on the nature of the glycosyl donor. As previously reported, with trichloroacetimidates the anticipated intramolecular Sakurai reaction proceeds efficiently and is an effective clock, whereas with sulfoxides complications arise. The source of these complications is now shown to be an intramolecular sulfenyl transfer reaction between the tethered allylsilane and the activated sulfoxide. These results illustrate how a different unimolecular clock reaction may be required for a given cation when it is generated from different donors in order to avoid side reactions. The synthesis and cyclization of a 2-O-(3-hydroxypropyl) glucopyranosyl sulfoxide leading on activation to the formation of a trans-fused acetal is also described. The formation of this crystallographically-established trans-fused acetal is discussed in terms of the high effective concentration of the intramolecular nucleophile which leads to a high degree of a SN2 character in the displacement of the α-glucsoyl triflate or at the level of the corresponding α-CIP. The possible use of such intramolecular alcohols as clock reactions and their limitations is discussed.
      Graphical abstract image

      PubDate: 2016-04-08T18:10:51Z
       
  • Editorial board
    • Abstract: Publication date: 29 April 2016
      Source:Carbohydrate Research, Volume 425




      PubDate: 2016-04-08T18:10:51Z
       
  • Graphical contents list
    • Abstract: Publication date: 29 April 2016
      Source:Carbohydrate Research, Volume 425




      PubDate: 2016-04-08T18:10:51Z
       
  • Improvement of the stereoselectivity of the glycosylation reaction with
           2-azido-2-deoxy-1-thioglucoside donors
    • Abstract: Publication date: Available online 29 March 2016
      Source:Carbohydrate Research
      Author(s): E.C. Lourenço, M.R. Ventura
      2-Azido-2-deoxy-1-thioglucoside donors with an electron withdrawing group at position 6 were employed to study the stereoselectivity of the glycosylation reaction with several acceptors, ranging from unhindered small primary alcohols to other sugars and steroids, using NIS/TfOH as promoter. p-Tolyl 2-azido-3,4-di-O-benzyl-6-O-chloroacetyl-2-deoxy-1-thio-α/β-D-glucopyranoside afforded the higher α-selectivity, showing that a stronger electron withdrawing ester at O-6 influenced the anomeric selectivity towards the 1,2-cis glucosides. The anomeric stereoselectivity was highly dependent on the acceptor.
      Graphical abstract image

      PubDate: 2016-04-02T18:07:17Z
       
  • Synthesis of oligosaccharides using per-o-trimethylsilyl-glycosyl iodides
           as glycosyl donor
    • Abstract: Publication date: Available online 29 March 2016
      Source:Carbohydrate Research
      Author(s): Hong Wang, Yanli Cui, Rong Zou, Zhaodong Cheng, Weirong Yao, Yangyi Mao, Yongmin Zhang
      Trimethylsilyl (TMS) protecting group has been found to be very useful for the simultaneous protection of both the glycosyl donor- and the acceptor-substrates in oligosaccharide synthesis. Thus, while the per-O-trimethylsilylated glycosyl iodides served as the glycosyl donor, those bearing selectively exposed primary hydroxyl groups were found suitable as the glycosyl acceptor for the reaction. The cheap and commercially available trialkylamine, triethylamine was found to be an effective promoter for the glycosylation. Importantly, the reaction was α-stereospecific and gave the products in 58% to 78% yields.
      Graphical abstract image

      PubDate: 2016-04-02T18:07:17Z
       
  • Synthesis of a trisaccharide repeating unit of the o-antigen from
           burkholderia anthina and its dimer
    • Abstract: Publication date: Available online 30 March 2016
      Source:Carbohydrate Research
      Author(s): Xueyun Geng, Lizhen Wang, Guofeng Gu, Zhongwu Guo
      A trisaccharide repeating unit of the O-antigen from Burkholderia anthina, α-L-Rha-(1→2)-α-L-Rha-(1→2)-β-D-Gal-O(CH2)3NH2 (1), and its dimer, α-L-Rha-(1→2)-α-L-Rha-(1→2)-α-D-Gal-(1→3)-α-L-Rha-(1→2)-α-L-Rha-(1→2)-β-D-Gal-O(CH2)3NH2 (2), were synthesized via a highly convergent and efficient assembly strategy. Sequential glycosylation of galactosyl acceptor 6 with rhamnosyl thioglycoside 7, followed by condensation of the resulting disaccharide acceptor 9 with rhamnosyl imidate donor 10, gave the title molecule 1 after global deprotection. The title hexasaccharide 2 was assembled in a convergent [2+2+2] manner, in which α-1,2-linked disaccharide 12 was initially obtained by the coupling reaction of disarmed thiorhamnoside acceptor 15 with armed thiogalactoside donor 14. Sequential glycosylation of disaccharide acceptor 9 with thioglycoside donors 12 and 13 afforded the target compound 2 after global deprotection.
      Graphical abstract image

      PubDate: 2016-04-02T18:07:17Z
       
  • Structures and genetics of biosynthesis of glycerol 1-phosphate-containing
           O–polysaccharides of Escherichia coli O28ab, O37, and O100
    • Abstract: Publication date: Available online 29 March 2016
      Source:Carbohydrate Research
      Author(s): Alexander S. Shashkov, Baopeng Yang, Sofya N. Senchenkova, Andrei V. Perepelov, Bin Liu, Yuriy A. Knirel
      O-polysaccharides of E. coli O28ab, O37, and O100 were found to contain glycerol 1–phosphate and the following structures of their oligosaccharide repeats were established by sugar analysis, Smith degradation (for O28ab), 1D and 2D 1H, 13C, and 13P NMR spectroscopy: Functions of putative glycosyltransferases genes in the O-antigen gene clusters of the strains studied were tentatively assigned based on similarities to genes of other E. coli O-serogroups available from GenBank and taking into account the O-polysaccharide structures established.
      Graphical abstract image

      PubDate: 2016-04-02T18:07:17Z
       
  • DFT/PCM theoretical study of the conversion of methyl
           4-o-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated
           derivative into their 3,6-anhydro counterparts
    • Abstract: Publication date: Available online 21 March 2016
      Source:Carbohydrate Research
      Author(s): Vanina A. Cosenza, Diego A. Navarro, Carlos A. Stortz
      Modeling of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate (2) and 2,6-disulfate (1) into methyl 3,6-anhydro-4-O-methyl-α-d-galactopyranoside (4) and its 2-sulfate (3), respectively (Scheme 1) has been carried out using DFT at the M06-2X/6-311+G(d,p)//M06-2X/6-31+G(d,p) level with the polarizable continuum model (PCM) in water. The three steps necessary for the alkaline transformation of 6-sulfated (and 2,6-disulfated) galactose units into 3,6-anhydro derivatives were evaluated. The final substitution step appears to be the rate limiting, involving an activation energy of ca. 23 kcal/mol. The other two steps (deprotonation and chair inversion) combined involve lower activation energies (9-12 kcal/mol). Comparison of the thermodynamics and kinetics of the reactions suggest that if the deprotonation step precedes the chair inversion, the reaction should be faster for both compounds. No major differences in reaction rate can be theoretically predicted to be caused by the presence of sulfate on O-2, although one experimental result suggested that O-2 sulfation should increase the reaction rate. The conformational pathways are complex, given the large number of rotamers available for each compound, and the way that some of these rotamers combine into some of the pathways. In any case, the conformation OS2 appears as a common intermediate for the chair inversion processes.
      Graphical abstract image

      PubDate: 2016-03-23T18:15:23Z
       
  • Synthesis of a hybrid type n-glycan heptasaccharide oxazoline for endo m
           catalysed glycosylation
    • Abstract: Publication date: Available online 23 March 2016
      Source:Carbohydrate Research
      Author(s): Pragya Priyanka, Antony J. Fairbanks
      Endo-β-N-acetylglucosaminidases (ENGases) are versatile biocatalysts that allow access to a wide variety of defined homogenous N-linked glycoconjugates in a convergent manner. A hybrid-type N-glycan was accessed by total synthesis, converted to an oxazoline, and used as a donor substrate with both wild type Endo M and an N175Q glycosynthase Endo M mutant allowing the convergent synthesis of a glycosylated amino acid bearing a hybrid N-glycan structure.
      Graphical abstract image

      PubDate: 2016-03-23T18:15:23Z
       
  • The structure of o-polysaccharides isolated from plant pathogenic bacteria
           pectobacterium wasabiae IFB5408 and IFB5427
    • Abstract: Publication date: Available online 22 March 2016
      Source:Carbohydrate Research
      Author(s): Karolina Ossowska, Małgorzata Czerwicka, Wojciech Sledz, Sabina Zoledowska, Agata Motyka, Sylwia Szulta, Ewa Lojkowska, Zbigniew Kaczyński
      O-polysaccharides were isolated from the lipopolysaccharides of two strains of plant pathogenic bacteria Pectobacterium wasabiae isolated in Poland in 2013 (IFB5408 and IFB5427). The purified polysaccharides were analyzed using 1D and 2D NMR spectroscopy (1H, DQF-COSY, TOCSY, ROESY, HSQC, HSQC-TOCSY, and HMBC) and the chemical methods. Sugar and methylation analyses of native polysaccharides, absolute configuration assignment of constituent monosaccharides together with NMR spectroscopy data revealed that the chemical structures of both O-polysaccharides are the same.
      Graphical abstract image

      PubDate: 2016-03-23T18:15:23Z
       
  • Linear synthesis of the hexasaccharide related to the repeating unit of
           the O-antigen from Shigella flexneri serotype 1d (I: 7,8)
    • Abstract: Publication date: Available online 21 March 2016
      Source:Carbohydrate Research
      Author(s): Ankita Mitra, Balaram Mukhopadhyay
      Total synthesis of the hexasaccharide repeating unit of the O-antigen from Shigella flexneri serotype 1d (I: 7,8), α-D-Glcp-(1→3)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-L-Rhap-(1→3)-[α-D-Glcp-(1→4)]-β-D-GlcpNAc, is reported by following a linear strategy. The target hexasaccharide was synthesized by sequential glycosylations of suitably protected monosaccharide derivatives prepared from commercially available monosaccharides through rational protecting group manipulations. Stereoselective glycosylations were accomplished by the activation of thioglycoside using N-iodosuccinimide and H2SO4-silica. The use of H2SO4-silica in place of traditional promoters like TfOH or TMSOTf was proved to be a better option for the NIS-mediated thiglycoside activation.
      Graphical abstract image

      PubDate: 2016-03-23T18:15:23Z
       
  • Statistical model semiquantitatively approximates
           arabinoxylooligosaccharides structural diversity
    • Abstract: Publication date: Available online 17 March 2016
      Source:Carbohydrate Research
      Author(s): Gleb Dotsenko, Michael Krogsgaard Nielsen, Lene Lange
      A statistical model describing the random distribution of substituted xylopyranosyl residues in arabinoxylooligosaccharides is suggested and compared with existing experimental data. Structural diversity of arabinoxylooligosaccharides of various length, originating from different arabinoxylans (wheat flour arabinoxylan (arabinose/xylose, A/X = 0.47); grass arabinoxylan (A/X = 0.24); wheat straw arabinoxylan (A/X = 0.15); and hydrothermally pretreated wheat straw arabinoxylan (A/X = 0.05)), is semiquantitatively approximated using the proposed model. The suggested approach can be applied not only for prediction and quantification of arabinoxylooligosaccharides structural diversity, but also for estimate of yield and selection of the optimal source of arabinoxylan for production of arabinoxylooligosaccharides with desired structural features.
      Graphical abstract image

      PubDate: 2016-03-19T11:45:13Z
       
  • Synthesis of AB4-type carbohydrate scaffolds as branching units in the
           glycosciences
    • Abstract: Publication date: Available online 3 March 2016
      Source:Carbohydrate Research
      Author(s): Tobias-Elias Gloe, Anne Müller, Anna Ciuk, Tanja M. Wrodnigg, Thisbe K. Lindhorst
      Carbohydrate scaffolds, functionalised according to an AB4-type, were prepared on the basis of α-d-mannopyranosides with various ethyl aglycone moieties, functionalised with ‘A’. Four functional groups ‘B’ were installed at positions 2, 3, 4, and 6 of the sugar ring. In particular, we were interested in preparing N3(NH2)4-functionalised mannosides as multifunctional branching units for further orthogonal derivatisation or immobilisation on surfaces. A detailed synthetic study was performed which revealed that an azido function ‘A’ had to be installed at an advanced stage of the synthesis for successful preparation of the desired AB4-type carbohydrate scaffolds. The most successful synthetic sequence involved tetra-cyanoethylation of a 2-benzyloxyethyl mannopyranoside and subsequent reduction with in situ Boc protection to achieve (NHBoc)4 functionalisation. Finally, the benzyloxyethyl aglycon was converted into the corresponding azidoethyl moiety to gain access to the desired N3(NHBoc)4-functionalised carbohydrate scaffold. Its utilisation was exemplified by straightforward synthesis of a photosensitive glycoconjugate and a tetravalent glycocluster. Such compounds may be immobilised on functional surfaces to serve as tools in cell adhesion studies.
      Graphical abstract image

      PubDate: 2016-03-08T07:20:54Z
       
 
 
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