for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> CHEMISTRY (Total: 767 journals)
    - ANALYTICAL CHEMISTRY (45 journals)
    - CHEMISTRY (531 journals)
    - CRYSTALLOGRAPHY (22 journals)
    - ELECTROCHEMISTRY (25 journals)
    - INORGANIC CHEMISTRY (40 journals)
    - ORGANIC CHEMISTRY (40 journals)
    - PHYSICAL CHEMISTRY (64 journals)

CHEMISTRY (531 journals)                  1 2 3 4 5 6 | Last

2D Materials     Hybrid Journal  
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 31)
ACS Catalysis     Full-text available via subscription   (Followers: 23)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 13)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 7)
ACS Macro Letters     Full-text available via subscription   (Followers: 17)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 24)
ACS Nano     Full-text available via subscription   (Followers: 216)
ACS Photonics     Full-text available via subscription   (Followers: 2)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 8)
Acta Chemica Iasi     Open Access  
Acta Chimica Slovaca     Open Access   (Followers: 5)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access   (Followers: 1)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 2)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 4)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 8)
Advanced Functional Materials     Hybrid Journal   (Followers: 32)
Advances in Chemical Engineering and Science     Open Access   (Followers: 21)
Advances in Chemical Science     Open Access   (Followers: 8)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 13)
Advances in Drug Research     Full-text available via subscription   (Followers: 16)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 7)
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: 11)
Advances in Nanoparticles     Open Access   (Followers: 10)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Polymer Science     Hybrid Journal   (Followers: 38)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 10)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 4)
African Journal of Chemical Education     Open Access   (Followers: 1)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 1)
Afrique Science : Revue Internationale des Sciences et Technologie     Open Access  
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alchemy     Open Access   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 4)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Applied Sciences     Open Access   (Followers: 27)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 130)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 11)
American Journal of Chemistry     Open Access   (Followers: 17)
American Journal of Plant Physiology     Open Access   (Followers: 9)
American Mineralogist     Full-text available via subscription   (Followers: 2)
Analyst     Full-text available via subscription   (Followers: 34)
Angewandte Chemie     Hybrid Journal   (Followers: 12)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 179)
Annales UMCS, Chemia     Open Access   (Followers: 2)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 1)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 2)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 10)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 11)
Anti-Infective Agents     Hybrid Journal   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 4)
Applied Spectroscopy     Full-text available via subscription   (Followers: 12)
Applied Surface Science     Hybrid Journal   (Followers: 14)
Arabian Journal of Chemistry     Full-text available via subscription   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 4)
Autophagy     Full-text available via subscription  
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 6)
Biochemistry     Full-text available via subscription   (Followers: 163)
Biochemistry Insights     Open Access   (Followers: 4)
Biochemistry Research International     Open Access   (Followers: 4)
BioChip Journal     Hybrid Journal   (Followers: 1)
Bioinorganic Chemistry and Applications     Open Access   (Followers: 4)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 1)
Biointerphases     Open Access  
Biomacromolecules     Full-text available via subscription   (Followers: 17)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 5)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 2)
BioNanoScience     Partially Free   (Followers: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 30)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 24)
Bioorganic Chemistry     Hybrid Journal   (Followers: 5)
Biopolymers     Hybrid Journal   (Followers: 12)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 11)
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: 1)
Carbohydrate Research     Hybrid Journal   (Followers: 10)
Carbon     Hybrid Journal   (Followers: 34)
Catalysis for Sustainable Energy     Open Access   (Followers: 1)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 4)
Catalysis Science and Technology     Free   (Followers: 4)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysts     Open Access   (Followers: 6)
Cellulose     Hybrid Journal   (Followers: 4)
Central European Journal of Chemistry     Hybrid Journal   (Followers: 5)

        1 2 3 4 5 6 | Last

Journal Cover Carbohydrate Research
   [12 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0008-6215 - ISSN (Online) 0008-6215
     Published by Elsevier Homepage  [2563 journals]   [SJR: 0.675]   [H-I: 77]
  • Quantitative fluorometric assay for the measurement of
           endo-1,4-β-glucanase
    • Abstract: Publication date: 18 August 2014
      Source:Carbohydrate Research, Volume 395
      Author(s): D. Mangan , B.V. McCleary , A. Liadova , R. Ivory , N. McCormack
      There is a growing demand for research tools to aid the scientific community in the search for improved cellulase enzymes for the biofuel industry. In this work, we describe a novel fluorometric assay for cellulase (endo-1,4-β-glucanase) which is based on the use of 4,6-O-benzylidene-4-methylumbelliferyl-β-cellotrioside (BzMUG3) in the presence of an ancillary β-glucosidase. This assay can be used quantitatively over a reasonable linear range, or qualitatively as a solution screening tool which may find extensive use in the area of metagenomics.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Functional identification of a galactosyltransferase critical to
           Bacteroides fragilis Capsular Polysaccharide A biosynthesis
    • Abstract: Publication date: 18 August 2014
      Source:Carbohydrate Research, Volume 395
      Author(s): Jerry M. Troutman , Sunita Sharma , Katelyn M. Erickson , Christina D. Martinez
      Capsular Polysaccharide A (CPSA), a polymer of a four-sugar repeating unit that coats the surface of the mammalian symbiont Bacteroides fragilis, has therapeutic potential in animal models of Multiple Sclerosis and other autoinflammatory diseases. Genetic studies have demonstrated that CPSA biosynthesis is dependent primarily on a single gene cluster within the B. fragilis genome. However, the precise functions of the individual glycosyltransferases encoded by this cluster have not been identified. In this report each of these glycosyltransferases (WcfQ, WcfP, and WcfN) have been expressed and tested for their function in vitro. Using a reverse phase high performance liquid chromatography (HPLC) assay, WcfQ and WcfP were found to transfer galactose from uridine diphosphate (UDP)-linked galactose (Gal) to N-acetyl-4-amino-6-deoxy-galactosamine (AADGal) linked to a fluorescent mimic of bactoprenyl diphosphate, the native isoprenoid anchor for bacterial polysaccharide biosynthesis. The incorporation of galactose to form a bactoprenyl-linked disaccharide was confirmed by radiolabel incorporation and mass spectrometry (MS) of purified product. Using varying concentrations of UDP-Gal and enzyme, WcfQ was found to be the most effective protein at transferring galactose, and is the most likely candidate for in vivo incorporation of the sugar. WcfQ also cooperated in the presence of three preceding biosynthetic enzymes to form an isoprenoid-linked disaccharide in a single-pot reaction. This work represents a critical step in understanding the biosynthetic pathway responsible for the formation of CPSA, an unusual and potentially therapeutic biopolymer.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Synthesis and evaluation of α-, β-glucosidase inhibition of
           1-N-carboxamide-1-azafagomines and 5-epi-1-azafagomines
    • Abstract: Publication date: 18 August 2014
      Source:Carbohydrate Research, Volume 395
      Author(s): Raquel Mendes , Vera C.M. Duarte , António Gil Fortes , Maria J. Alves
      1-N-Carboxamide 1-azafagomines and 5-epi-1-azafagomines were obtained from 1-azafagomine and 5-epi-1-azafagomine. The hydroxyl groups and the N-2 pyridazine position were protected prior to reaction with different isocyanates to form ureas. Protective groups were removed leading to the target compounds in 18–23% global yields. Final compounds were tested towards α- and β-glucosidases.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Determination of native capsular polysaccharide structures of
           Streptococcus pneumoniae serotypes 39, 42, and 47F and comparison to
           genetically or serologically related strains
    • Abstract: Publication date: 18 August 2014
      Source:Carbohydrate Research, Volume 395
      Author(s): Bent O. Petersen , Sebastian Meier , Berit Smestad Paulsen , Antonio R. Redondo , Ian C. Skovsted
      The diversity of capsular polysaccharides of the bacterial pathogen Streptococcus pneumoniae leads to at least 91 different serotypes. While the genetic loci for capsular biosynthesis have been characterized for all serotypes, the determination of resultant polysaccharide structures remains incomplete. Here, we report the chemical structures of the capsular polysaccharides of serotypes 39, 42, and 47F from the genetic cluster 4, and discuss the structures in the context of structures from serologically and genetically related serotypes. Antigenic determinants can be approximated in this manner. The structure of the serotype 39 capsular polysaccharide is and has identical composition to the capsular polysaccharide 10A, but two different linkages. The serotype 42 structure closely resembles the genetically related serotype 35A, which does not contain residue A. The structure of the serotype 47F capsular polysaccharide is somewhat different from a recently determined structure from the same serogroup, while containing a structural motif that is reflected in serotype 35A and 42 capsular polysaccharide structures, thus explaining the cross-reactivity of serotype 47F with the typing serum 35a.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • A partially methylated mannogalactan from hybrid mushroom pfle 1p:
           purification, structural characterization, and study of immunoactivation
    • Abstract: Publication date: 18 August 2014
      Source:Carbohydrate Research, Volume 395
      Author(s): Prasenjit Maity , Manabendra Pattanayak , Saikat Maity , Ashis K. Nandi , Ipsita K. Sen , Birendra Behera , Tapas K. Maiti , Pijush Mallick , Samir R. Sikdar , Syed S. Islam
      A new water-soluble heteropolysaccharide (PS-II) with apparent molecular weight ∼1.65×105 Da, was isolated from the fruiting bodies of hybrid mushroom pfle 1p by hot aqueous extraction. It is composed of d-mannose, d-galactose, and 3-O-Me-d-galactose in a molar ratio of 1.0:0.99:1.1. The structural investigation of PS-II has been carried out using acid hydrolysis, methylation analysis, periodate oxidation study, and 1D/2D NMR experiments. Based on the results of these experiments, it was established that PS-II contained a main chain of (1→6) linked α-d-galactopyranosyl residues, one of which was substituted at C-2 by a terminal mannopyranosyl residue and also methylated at C-3 position. This heteropolysaccharide (PS-II) exhibited macrophage activation by NO production as well as in vitro splenocyte and thymocyte stimulation.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Optical nonlinearity and electric conductivity origin study on sucrose
           crystal by using IR, Raman, INS, NMR, and EPR spectroscopies
    • Abstract: Publication date: 18 August 2014
      Source:Carbohydrate Research, Volume 395
      Author(s): M. Magdalena Szostak , Katarzyna Piela , Krystyna Hołderna-Natkaniec , Ireneusz Natkaniec , Ewa Bidzińska
      The supposed importance of hydrogen bonds toward the origin of second harmonic generation (SHG) and electric conductivity in crystalline sucrose was investigated by IR (4000–10cm−1), INS (2000–10cm−1, at 35K), polarized Raman (3600–50cm−1) spectra, and 1H NMR second moment line records in the temperature range 450–80K. The temperature dependence of NIR (7000–5500cm−1) polarized spectra gave information about –CH2 motions complementary to NMR results concerning –CH2OH group rearrangements. The EPR spectra were applied to study the generation of radical ions by exposure to NIR radiation. Density functional theory quantum chemical calculations were performed to reproduce the vibrational spectra in order to complete as far as possible the assignments of bands observed by us and in the literature in sucrose crystals, and to throw more light on the possible reasons of sucrose electric conductivity and optical nonlinearity by the knowledge of theoretical values of dipole moments, polarizabilities, first order hyperpolarizabilities of sucrose molecule and clusters as well as ionization energy and electron affinity. The proton transfer in one specific hydrogen bond parallel to the helical axis b is proposed to be the most important in SHG and conductivity origin.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • A Propos of Glycosyl Cations and the Mechanism of Chemical Glycosylation;
           the Current State of the Art
    • Abstract: Publication date: Available online 1 July 2014
      Source:Carbohydrate Research
      Author(s): Luis Bohé , David Crich
      An overview of recent advances in glycosylation with particular emphasis on mechanism is presented. The mounting evidence for both the existence of glycosyl oxocarbenium ions as fleeting intermediates in some reactions, and the crucial role of the associated in counter ion in others is discussed. The extremes of the SN1 and SN2 manifolds for the glycosylation reaction are bridged by a continuum of mechanisms in which it appears likely that most examples are located.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Synthesis and Evaluation of Glyco-coated Liposomes as Drug Carriers for
           Active Targeting in Drug Delivery Systems
    • Abstract: Publication date: Available online 1 July 2014
      Source:Carbohydrate Research
      Author(s): Akiharu Ueki , Keita Un , Yuka Mino , Mitsuru Yoshida , Shigeru Kawakami , Hiromune Ando , Hideharu Ishida , Fumiyoshi Yamashita , Mitsuru Hashida , Makoto Kiso
      Novel sugar-conjugated cholesterols, β-Gal-, α-Man-, β-Man-, α-Fuc-, and β-Man-6P-S-β-Ala-Chol, were synthesized and incorporated into liposomes. In vitro experiments using the glyco-coated liposomes showed that the glyco-coated liposomes are efficiently taken up by cells expressing carbohydrate-binding receptors selectively. Glyco-coated liposomes are promising candidates for drug delivery vehicles.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Re -Visiting The Structure Of Heparin
    • Abstract: Publication date: Available online 3 July 2014
      Source:Carbohydrate Research
      Author(s): Benito Casu , Annamaria Naggi , Giangiacomo Torri
      The sulfated polysaccharide heparin has been used as a life-saving anticoagulant in clinics well before its detailed structure was known. This mini-review is a survey of the evolution in the discovery of the primary and secondary structure of heparin. Highlights in this history include elucidation and synthesis of the specific sequence that binds to antithrombin, the development of low-molecular weight heparins currently used as antithrombotic drugs, and the most promising start of chemo-enzymatic synthesis. Special emphasis is given to peculiar conformational properties contributing to interaction with proteins that modulate different biological properties.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Generation and Structural Validation of A Library of Diverse
           Xyloglucan-Derived Oligosaccharides, Including An Update on Xyloglucan
           Nomenclature
    • Abstract: Publication date: Available online 8 July 2014
      Source:Carbohydrate Research
      Author(s): Sami T. Tuomivaara , Katsuro Yaoi , Malcolm A. O’Neill , William S. York
      Xyloglucans are structurally complex plant cell wall polysaccharides that are involved in cell growth and expansion, energy metabolism and signaling. Determining the structure-function relationships of xyloglucans would benefit from the availability of a comprehensive and structurally diverse collection of rigorously characterized xyloglucan oligosaccharides. Here, we present a workflow for the semi-preparative scale generation and purification of neutral and acidic xyloglucan oligosaccharides using a combination of enzymatic and chemical treatments and size-exclusion chromatography. Twenty-six of these oligosaccharides were purified to near homogeneity and their structures validated using a combination of matrix-assisted laser desorption/ionization mass spectrometry, high-performance anion exchange chromatography and 1H-nuclear magnetic resonance spectroscopy. Mass spectrometry and analytical chromatography were compared as methods for xyloglucan oligosaccharide quantification. 1H chemical shifts were assigned using two-dimensional correlation spectroscopy. A comprehensive update of the nomenclature describing xyloglucan side-chain structures is provided for reference.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Hyaluronic acid-modified multiwalled carbon nanotubes for targeted
           delivery of doxorubicin into cancer cells
    • Abstract: Publication date: Available online 8 July 2014
      Source:Carbohydrate Research
      Author(s): Xueyan Cao , Lei Tao , Shihui Wen , Wenxiu Hou , Xiangyang Shi
      Development of novel drug carriers for targeted cancer therapy with high efficiency and specificity is of paramount importance and has been one of the major topics in current nanomedicine. Here we report a general approach to using multifunctional multiwalled carbon nanotubes (MWCNTs) as a platform to encapsulate an anticancer drug doxorubicin (DOX) for targeted cancer therapy. In this approach, polyethyleneimine (PEI)-modified MWCNTs were covalently conjugated with fluorescein isothiocyanate (FI) and hyaluronic acid (HA). The formed MWCNT/PEI-FI-HA conjugates were characterized via different techniques and were used as a new carrier system to encapsulate the anticancer drug doxorubicin for targeted delivery to cancer cells overexpressing CD44 receptors. We show that the formed MWCNT/PEI-FI-HA/DOX complexes with a drug loading percentage of 72% are water soluble and stable. In vitro release studies show that the drug release rate under an acidic condition (pH 5.8, tumor cell microenvironment) is higher than that under physiological condition (pH 7.4). Cell viability assay demonstrates that the carrier material has good biocompatibility in the tested concentration range, and the MWCNT/PEI-FI-HA/DOX complexes can specifically target cancer cells overexpressing CD44 receptors and exert growth inhibition effect to the cancer cells. The developed HA-modified MWCNTs hold a great promise to be used as an efficient anticancer drug carrier for tumor-targeted chemotherapy.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Octopus glycosides: Multivalent molecular platforms for testing
           carbohydrate recognition and bacterial adhesion
    • Abstract: Publication date: Available online 9 July 2014
      Source:Carbohydrate Research
      Author(s): Thisbe K. Lindhorst , Michael Dubber
      Multivalency of carbohydrate-protein interactions is critical for cell adhesion, including attachment of bacteria to their host cells. To investigate specific parameters of multivalency effects, a variety of multivalent glycoconjugates has been designed according to different mimetic approaches. Some 15 years ago, carbohydrates were elaborated as multivalent scaffold molecules for the preparation of carbohydrate-centred “octopus glycosides” as well as of other carbohydrate-centred glycoconjugates. The beginning of this research is reported from a historical perspective and a selection of interesting applications are highlighted.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Simple synthesis of glycosylthiols and thioglycosides by rearrangement of
           O-glycosyl thionocarbamates
    • Abstract: Publication date: Available online 9 July 2014
      Source:Carbohydrate Research
      Author(s): A. Kasprzycka , R. Komor , G. Pastuch Gawołek , W. Szeja
      The synthesis of thioglycosides has been achieved in a high yielding process employing thionocarbamates prepared from protected reducing sugars and N-alkyl isothiocyanate in the presence of a non-nucleophilic base (K2CO3). In the key step of the synthesis, thionocarbamates were treated with Lewis acid (TMSOTf) to give O,S-rearrangement products that were applied to the synthesis of both anomers of heteroaryl thioglycosides.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Database and data analysis application for structural characterization of
           gangliosides and sulfated glycosphingolipids by negative ion mass
           spectrometry
    • Abstract: Publication date: Available online 10 July 2014
      Source:Carbohydrate Research
      Author(s): Marko Rožman , Dragana Fabris , Tomislav Mrla , Željka Vukelić
      Gangliosides and sulfated glycosphingolipids, as building and functional components of animal cell membranes, participate in cell-to-cell interactions and signaling, but also in changes of cell architecture due to different pathophysiological events. In order to enable higher throughput and to facilitate structural characterization of gangliosides/sulfo- glycosphingolipids (GSL) and their neutral GSL counterparts by negative ion mass spectrometry (MS) and tandem MS techniques, a database and data analysis application have been developed. In silico developed glycosphingolipid database considers a high diversity of ceramide compositions, several sialic acid types (N-acetylneuraminic acid, N-glycolylneuraminic acid and 2-keto-3-deoxynononic acid) as well as possible additional substitutions/modifications of glycosphingolipids, such as O-acetylation, de-N-acetylation, fucosylation, glucuronosylation, sulfation, attachment of repeating terminal hexose-N-acetylhexosamine- (Hex-HexNAc-)1-6 extension and possible lactone forms. Data analysis application, named GSL-finder, enables correlation of negative ion MS and/or low-energy tandem MS spectra with the database structures. The GSL-database construction and the GSL-finder application searching rules are explained. Validation conducted on GD1a fraction as well as on complex mixtures of native gangliosides isolated from different mammalian brain tissues (human fetal and adult brain, and calf brain tissue) demonstrated agreement with previous studies. Plain, fast and automated routine for structural characterization of gangliosides/sulfated glycosphingolipids and their neutral GSL counterparts described here could facilitate and improve mass spectrometric analysis of complex glycosphingolipid mixtures originating from variety of normal and pathological biomaterial, where it is known that distinctive changes in glycosphingolipid composition occur.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Affinity of monoclonal antibodies for Globo-series glycans
    • Abstract: Publication date: Available online 14 July 2014
      Source:Carbohydrate Research
      Author(s): Chelcie H. Eller , Guangbin Yang , Ouathek Ouerfelli , Ronald T. Raines
      Globo-series glycans are human cell-surface carbohydrates that include stem-cell marker SSEA-4 and cancer-cell antigen Globo H. These two hexasaccharides differ only in their terminal saccharide: N-acetylneuraminic acid in SSEA-4 and l-fucose in Globo H. Herein, we evaluated the affinity of the monoclonal antibodies α-SSEA-4 and α-GH for the glycans SSEA-4 and Globo H. Using fluorescence polarization, we find that the two monoclonal antibodies have affinity for their cognate glycan in the low nanomolar range, and have negligible affinity for the non-cognate glycan. Using surface plasmon resonance, we find that each cognate affinity is ∼20-fold greater if the glycan is immobilized on a surface rather than free in solution. We conclude that the terminal saccharide plays a dominant role in the ability of monoclonal antibodies to recognize these Globo-series glycans and that the extraordinary specificity of these antibodies supports their use for identifying and sorting stem-cells (α-SSEA-4) and as an agent in cancer immunotherapy (α-GH).
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Synthesis of a heparin-related GlcN-IdoA sulfation-site variable
           disaccharide library and analysis by Raman and ROA spectroscopy
    • Abstract: Publication date: Available online 14 July 2014
      Source:Carbohydrate Research
      Author(s): Gavin J. Miller , Steen U. Hansen , Marek Baráth , Christian Johannessen , Ewan W. Blanch , Gordon C. Jayson , John M. Gardiner
      Synthesis of an array of differentially sulfated GlcN-IdoA disaccharides, accessible on good scale, directly from L-iduronate components is described. These are specifically directed to provide the sulfation variability at the key most common biologically relevant sulfation-variable L-idoA O-2 and DGlcN O-6 and amino sites of this heparin disaccharide. This sulfation-varied matrix has allowed the first evaluation of using Raman/ROA spectroscopy to characterize changes in spectra as a function of both site and level of sulfation with pure, defined heparin-related disaccharide species. This provides analysis of both similarities and differences to native digest heparin and this show evidence of different types of changes in conformations and conformational freedom as a function of some specific sulfation changes at the disaccharide level. It is anticipated that this data set will open the way for applications to further site-specific sulfated saccharides and demonstrates the capability offered by Raman-ROA towards fingerprinting sulfation in heparin fragments.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Synthesis of antifungal vaccines by conjugation of β-1,2
           2trimannosides with T-cell peptides and covalent anchoring of
           neoglycopeptide to tetanus toxoid
    • Abstract: Publication date: Available online 14 July 2014
      Source:Carbohydrate Research
      Author(s): Jonathan Cartmell , Eugenia Paszkiewicz , Pui-Hang Tam , Thanh Luu , Susmita Sarkar , Tomasz Lipinski , David R. Bundle
      Selective strategies for construction of novel three component glycoconjugate vaccines presenting Candida albicans cell wall glycan (β-1,2 mannoside) and polypeptide fragments on a tetanus toxoid carrier are described. The first of two conjugation strategies employed peptides bearing an N-terminal thiopropionyl residue for conjugation to a trisaccharide equipped with an acrylate linker and a C-terminal S-acetyl thioglycolyl moiety for subsequent linking of neoglycopeptide to bromoacetylated tetanus toxoid. Michael addition of acrylate trisaccharides to peptide thiol under mildly basic conditions gave a mixture of N- and C- terminal glyco-peptide thioethers. An adaptation of this strategy coordinated S-acyl protection with anticipated thioester exchange equilibria. This furnished a single chemically defined fully synthetic neoglycopeptide conjugate that could be anchored to tetanus toxoid carrier and avoids introduction of exogenous antigenic groups. The second strategy retained the N-terminal thiopropionyl residue but replaced the C-terminal S-acetate functionality with an azido group that allowed efficient, selective formation of neoglycopeptide thioethers and subsequent conjugation of these with propargylated tetanus toxoid, but introduced potentially antigenic triazole linkages.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Elucidation of Differences in N-Glycosylation between Different Molecular
           Weight Forms of Recombinant CLEC-2 by LC MALDI Tandem MS
    • Abstract: Publication date: Available online 16 July 2014
      Source:Carbohydrate Research
      Author(s): Lei Zhou , Yifan Qian , Xingwang Zhang , Yuanyuan Ruan , Shifang Ren , Jianxin Gu
      C-type lectin-like receptor 2 (CLEC-2) is a newly identified receptor expressed on the platelet surface. It has been reported that CLEC-2 exists as a higher molecular weight (HMW) and a lower molecular weight (LMW) form, which share the same protein core but differ in glycans. The two forms appear to have different ligand-binding ability, indicating that the differential glycosylation of CLEC-2 possibly produces functionally distinct glycoforms. This study aimed to explore an easy method to directly elucidate the N-glycosylation difference by employing a glycoproteomics approach. The off-line coupling of nano-LC with a MALDI-QIT-TOF mass spectrometer was demonstrated to be capable of sensitive and direct elucidation of the glycosylation difference between HMW and LMW CLEC-2, simultaneously providing information about their oligosaccharide structures and the glycosylation sites. The results reveal that a specific glycosylation site, Asn 134, is differently glycosylated in the two forms, with complex types of bi-antennary, tri-antennary and tetra-antennary, N-linked, fucosylated glycans identified at this site in the HMW form but not the LMW form. The observed difference in glycosylation might provide new insights into the underlying mechanisms of biological functions of CLEC-2. Because of its simplicity and sensitivity, the method explored in this work suggests that it holds promise as a method of elucidating differences in direct N-glycosylation of target glycoprotein, even in small amount of samples.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Additive-controlled Stereoselective Glycosylations of 2,3-Oxazolidinone
           Protected Glucosamine or Galactosamine Thioglycoside Donors with Phenols
           Based on Preactivation Protocol
    • Abstract: Publication date: Available online 16 July 2014
      Source:Carbohydrate Research
      Author(s): Qi Qin , De-Cai Xiong , Xin-Shan Ye
      Stereo-controllable glycosylation reactions of 2,3-oxazolidinone protected glucosamine thioglycoside donor with different phenol acceptors based on preactivation protocol, are described. It was found that BF3•Et2O worked as α-directing additive, while TTBP acted as β-directing additive. Simply by altering additives, either α-aryl glycosides or β-aryl glycosides were achieved in a stereoselective manner. The additives were also applied to the stereoselective glycosylation reactions of 2,3-oxazolidinoe protected galactosamine donor with phenol substrates.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Selective glycosylation of steroidal saponins by Arthrobacter
           nitroguajacolicus
    • Abstract: Publication date: Available online 16 July 2014
      Source:Carbohydrate Research
      Author(s): Jing-yuan Liu , Li Lu , Li-ping Kang , Yi-xun Liu , Yang Zhao , Cheng-qi Xiong , Yu-qin Zhang , Li-yan Yu , Bai-ping Ma
      In this study seven strains of the genus Arthrobacter were screened by biotransformation to discover glycosylating patterns on steroid saponins. A strain of Arthrobacter nitroguajacolicus (CPCC 203516) was found to have the ability of fructosylation. Crude enzyme of the strain was extracted for the further study of conversion characteristics and patterns. Sucrose was used as a non-activated sugar donor, and fifteen steroidal saponins were involved. Nine furostan saponins of the substrates were converted, and ten products were isolated and identified. Based on the HR-ESI-MS, 1D and 2D NMR spectral data, one fructosyl was added to furostan saponins at C6-OH of 26-O-β-D-glucopyranosyl by A. nitroguajacolicus for all nine products. One product was distinguished by an additional fructosyl at the position of C6-OH on the first added fructosyl. Spirostan saponins of the substrates could not be converted. Steroidal saponins embracing a fructosyl are quite rare according to other reports based on similar studies. This study successfully converted furostan saponins into new compounds.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Highly stereoselective synthesis of C-vinyl pyranosides via a Pd-mediated
           cycloetherification of 1-acetoxy-2,3-dideoxy-oct-2-enitols
    • Abstract: Publication date: Available online 16 July 2014
      Source:Carbohydrate Research
      Author(s): Ernest G. Nolen , Vivian C. Ezeh , Matthew J. Feeney
      Oct-2-enitols undergo a Pd°-mediated cyclization to produce C-vinyl α-gluco- and α-galactopyranosides, and C-vinyl β-mannopyranoside in good yield and with high stereoselectivity. While substrate control demonstrates a clear stereochemical preference during cyclization, the α- and β-epimeric ratios are enhanced by double diastereoselection using the (S,S) or (R,R)-DACH ligands.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Design and synthesis of 4’-O-alkyl-chitobiosyl-4-methylumbelliferone
           as human chitinase fluorogenic substrates
    • Abstract: Publication date: Available online 18 July 2014
      Source:Carbohydrate Research
      Author(s): Boudewijn A. Duivenvoorden , Karen Ghauharali , Saskia Scheij , Rolf G. Boot , Johannes M.F.G. Aerts , Gijsbert A. van der Marel , Herman S. Overkleeft , Jeroen D.C. Codée
      The synthesis of three fluorogenic chitobiosyl derivatives, modified at the non-reducing 4’-OH with, either a methyl, an isopropyl or a cyclohexylmethyl substituent, is described. The 4’-capped 4-methylumbelliferyl chitobiosides are hydrolysed by the human chitinase CHIT1 following Michaelis-Menten kinetics and in contrast to unmodified chitobiosyl-4-methylumbelliferone do not undergo transglycosylation. The compounds are also relatively poor hexosaminidase substrates and thus provide useful alternatives to 4’-deoxychitobiosyl-4-methylumbelliferone, previously reported by us as fluorogenic substrate to monitor CHIT1 activity as a marker for Gaucher disease state.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Synthesis and Characterization of Copolyanhydrides of Carbohydrate-based
           Galactaric Acid and Adipic Acid
    • Abstract: Publication date: Available online 19 July 2014
      Source:Carbohydrate Research
      Author(s): Tuomas Mehtiö , Leena Nurmi , Virpi Rämö , Hannu Mikkonen , Ali Harlin
      A series of copolyanhydrides, consisting of 2,3,4,5-tetra-O-acetyl-galactaric acid (AGA) and adipic acid (AA) as monomer units, was polymerized. Synthesis of AGA monomer consisted of two steps. First, O-acetylation of galactaric acid secondary hydroxyl groups was performed using acetic anhydride as a reagent. Acetic anhydride was then further used as a reagent in the synthesis of diacetyl mixed anhydride of AGA. Polymerizations were conducted as bulk condensation polymerization at 150 °C. Thermal properties of the copolymers varied depending on monomer composition. Increase in the AGA content had a clear increasing effect on the Tg . Similar increasing effect was observed in Tm . The degree of crystallinity decreased as AGA content increased. There was a slightly lowering tendency in the molecular weights of the obtained polymers when the AGA content in the polymerization mixtures increased. The described synthesis route shows that bio-based aldaric acid monomers are potential candidates for the adjustment of thermal properties of polyanhydrides.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Structure and gene cluster organization of the O-antigen of Providencia
           alcalifaciens O45:H25
    • Abstract: Publication date: Available online 21 July 2014
      Source:Carbohydrate Research
      Author(s): Olga G. Ovchinnikova , Alexander S. Shashkov , Magdalena Moryl , Bin Liu , Antoni Rozalski , Yuriy A. Knirel
      O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O45:H25 and studied by sugar analysis, Smith degradation, and 1H and 13C NMR spectroscopy. The following structure of the pentasaccharide repeat of the O-polysaccharide was established: The O-antigen gene cluster of P. alcalifaciens O45 was sequenced and found to be in full agreement with the O-polysaccharide structure established.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Identification of a new bis-amino acid glycoside selectively toxic to
           multiple myeloma cells
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Chao-Ying Cheng , Yan-Yan Feng , Yi Zang , Jia Li , Xiao-Peng He , Guo-Rong Chen
      A bis-triazolyl phenylalaninyl galactoside was synthesized by a two-fold click reaction between an azido phenylalanine and a di-O-propynyl galactoside. By a cytotoxicity assay the compound was determined to be selectively toxic for multiple myeloma (MM) among a series of cancer cell lines with no toxicity to a control cell line. A Western blot analysis suggested that this compound could potentiate the cleavage of poly ADP-ribose polymerase in MM cells, leading to apoptosis.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Useful approach to the synthesis of aryl thio- and selenoglycosides in the
           presence of rongalite
    • Abstract: Publication date: Available online 21 July 2014
      Source:Carbohydrate Research
      Author(s): Cheerladinne Venkateswarlu , Vibha Gautam , Srinivasan Chandrasekaran
      A simple, mild and cost effective methodology has been developed for the synthesis of aryl thio-and selenoglycosides from glycosyl halides and diaryl dichalcogenides. Diaryl dichalcogenides undergo reductive cleavage in the presence of rongalite (HOCH2SO2Na) to generate chalcogenate anion in situ followed by reaction with glycosyl halides to furnish the corresponding aryl thio- and selenoglycosides in excellent yields. Using this protocol, synthesis of 4-methyl-7-thioumbelliferyl-β-D-cellobioside (MUS-CB), a fluorescent non-hydrolyzable substrate analogue for cellulases has been achieved.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Chemical synthesis of a tetrasaccharide related to the exocellular
           polysaccharide from Rhodococcus sp. RHA1
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Darshita Budhadev , Balaram Mukhopadhyay
      Chemical synthesis of the tetrasaccharide related to the exocellular polysaccharide from Rhodococcus sp. RHA1 is reported. The stereoselective glycosylations were achieved by activation of the thioglycoside donors using N-iodosuccinimide in the presence of La(OTf)3 varying temperature per the need of 1,2-cis or 1,2-trans glycosylations. The target tetrasaccharide is reported in the form of its p-methoxyphenyl glycoside that can be cleaved selectively from the per-O-acetylated derivative allowing further glycoconjugate formation using trichloroacetimidate chemistry.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Editorial board
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394




      PubDate: 2014-07-27T19:35:12Z
       
  • Graphical contents list
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394




      PubDate: 2014-07-27T19:35:12Z
       
  • Revisiting synthetic preparation of the quorum sensing substrate
           S-d-ribosyl-l-homocysteine (SRH)
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Megan E. Bolitho , Brendan J. Corcoran , Emily I. Showell-Rouse , Keeshia Q. Wang
      Cleavage of the thioether bond of S-d-ribosyl-l-homocysteine (SRH) by the enzyme S-ribosylhomocysteinase (LuxS) serves as the final biosynthetic step in the generation of the quorum sensing autoinducer AI-2 by bacteria. Herein, a revised chemical synthesis of SRH is presented at convenient scale and purity for in vitro studies of LuxS. Potassium bis(trimethylsilyl)amide (KHMDS) is identified as a judicious base for the formation of the thioether of the target compound from readily-accessible precursors: a thiol nucleophile derived from l-homocystine and a sulfonate-activated d-ribosyl electrophile. The exclusive use of acid-labile protecting groups allows for facile deprotection to the final product, producing the TFA salt of SRH in five synthetic steps and 26% overall yield. The chemically-synthesized material is isolated at high purity and demonstrated to serve as the LuxS substrate by an in vitro assay.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • A simplified procedure for gram-scale production of sialylglycopeptide
           (SGP) from egg yolks and subsequent semi-synthesis of Man3GlcNAc oxazoline
           
    • Abstract: Publication date: Available online 27 July 2014
      Source:Carbohydrate Research
      Author(s): Bingyang Sun , Wenzheng Bao , Xiaobo Tian , Mingjing Li , Hong Liu , Jinhua Dong , Wei Huang
      Heterogeneity of glycan structures in native glycoconjugates always hampers precise studies on carbohydrate-involved biological functions. To construct homogeneous glycoconjugates from natural resource of homogeneous glycans is therefore a practical approach to solve this problem. We report here an optimized procedure for gram-scale production of sialoglycopeptide (SGP) containing a disialyl biantennary complex-type N-glycan from egg yolks. Our new procedure simplified the extraction process by treating the egg yolk powder with 40% acetone, avoiding massive emulsification, high-speed centrifugation, and sophisticated chromatography in reported methods. Subsequent semi-synthesis of the N-glycan core Man3GlcNAc oxazoline from SGP was accomplished for the first-time via glyco-trimming and successive oxazoline formation. This efficient semi-synthesis provides an alternative to the pure chemical approach that involves multi-step total synthesis and facilitates the application of Endo-glycosidase-enabled chemoenzymatic synthesis of various homogeneous glycoconjugates.
      Graphical abstract image Highlights

      PubDate: 2014-07-27T19:35:12Z
       
  • Synthesis of octitols and the respective amino-derivatives from
           ‘organo-aldols’
    • Abstract: Publication date: Available online 27 July 2014
      Source:Carbohydrate Research
      Author(s): Katarzyna Łęczycka , Bartosz Chaciak , Maciej Cieplak , Piotr Cmoch , Sławomir Jarosz
      Two diastereoisomeric keto-octoses, obtained in there action of 2,3:4,5-diacetone-D-arabino se with protected dihydroxyacetone catalyzed with L- or D-proline, were converted into octitols by stereoselective reduction of the carbonyl group with zinc borohydride and final deprotection. The study on the preparation of the respective amino-derivatives by reductive amination of these organo-adducts is presented; stereochemical aspects of these processes are discussed.
      Graphical abstract image

      PubDate: 2014-07-27T19:35:12Z
       
  • Fucosylation of triethyleneglycol-based acceptors into
           “clickable” α-fucosides
    • Abstract: Publication date: Available online 14 June 2014
      Source:Carbohydrate Research
      Author(s): Shuai Wang , Nicolas Galanos , Audric Rousset , Kevin Buffet , Samy Cecioni , Dominique Lafont , Stéphane P. Vincent , Sébastien Vidal
      Design of multivalent glycoconjugates can find applications such as in anti-adhesive therapy against bacterial infections. Nevertheless, the access to such macromolecules requires functionalized building blocks prepared in a minimum number of steps and on a multi-gram scale at least for the laboratory. Fucose is a representative epitope used by several bacteria for adhesion to their host cells. The stereoselective, rapid and efficient access to two “clickable” α-fucosides was re-investigated using PPh3/CBr4-promoted glycosylation of chloro- (as precursors of azido-) and alkyne-functionalized triethyleneglycols with fully unprotected L-fucose. The convenient access to such building blocks paves the way to the design of new multivalent glycoconjugates functionalized with fucose epitopes and their applications.
      Graphical abstract image Highlights

      PubDate: 2014-06-14T15:16:04Z
       
  • Gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid
           conjugate of arabinogalactan as a potential liver-targeting magnetic
           resonance imaging contrast agent
    • Abstract: Publication date: Available online 6 June 2014
      Source:Carbohydrate Research
      Author(s): Yan Xiao , Rong Xue , Tianyan You , Xiaojing Li , Fengkui Pei , Xuxia Wang , Hao Lei
      A novel biocompatible macromolecule (AG-CM-EDA-DOTA-Gd) was synthesized as a liver magnetic resonance imaging (MRI) contrast agent. AG-CM-EDA-DOTA-Gd consisted of a carboxymethyl-arabinogalactan unit conjugated with gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (Gd-DOTA) via ethylenediamine, and was specifically designed to bind to hepatocyte asialoglycoprotein in vivo, in an effort to develop a potential new tool for the diagnosis of liver diseases. The T1-relaxivity (8.78 mmol-1·L·s-1) of AG-CM-EDA-DOTA-Gd was 1.86 times than that of Gd-DOTA (4.76 mmol-1·L·s-1) in D2O at 9.4 T and 25 °C. MRI experiments showed significant enhancement in rat liver following the intravenous administration of AG-CM-EDA-DOTA-Gd (0.094 mmol Gd3+/kg body weight), which persisted for longer than Gd-DOTA (0.098 mmol Gd3+/kg body weight). The mean percentage enhancements in the liver parenchyma were 85.2±6.5% and 19.3±3.3% for AG-CM-EDA-DOTA-Gd and Gd-DOTA, respectively. The results of this study therefore indicate that AG-CM-EDA-DOTA-Gd could be used as a potential liver-targeting contrast agent for MRI.
      Graphical abstract image Highlights

      PubDate: 2014-06-14T15:16:04Z
       
  • Graphical contents list
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393




      PubDate: 2014-06-14T15:16:04Z
       
  • Access to bifunctionalized biomolecular platforms using oxime ligation
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Karel Křenek , Radek Gažák , Gour Chand Daskhan , Julian Garcia , Michele Fiore , Pascal Dumy , Miroslav Šulc , Vladimír Křen , Olivier Renaudet
      This paper describes an efficient oxime ligation strategy to prepare multivalent conjugates wherein peptides alone or in combination with carbohydrate or oxime groups were coupled to a cyclopeptide scaffold. To demonstrate the versatility of this approach, two classes of conjugates have been prepared. In one class, we attached two or four peptide sequences to the cyclopeptide core together with free oxime groups, while the second class contains an additional substitution with four or two monosaccharides. The well-defined structure of these conjugates was confirmed by high-resolution mass spectrometry.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Editorial board
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393




      PubDate: 2014-06-14T15:16:04Z
       
  • Synthesis of the allelochemical alliarinoside present in garlic mustard
           (Alliaria petiolata), an invasive plant species in North America
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Carl Erik Olsen , Birger Lindberg Møller , Mohammed Saddik Motawia
      The allelochemical alliarinoside present in garlic mustard (Alliaria petiolata), an invasive plant species in North America, was chemically synthesized using an efficient and practical synthetic strategy based on a simple reaction sequence. Commercially available 1,2,3,4,6-penta-O-acetyl-β-d-glucopyranose was converted into prop-2-enyl 2′,3′,4′,6′-tetra-O-acetyl-β-d-glucopyranoside and subjected to epoxidation. In a one-pot reaction, ring-opening of the epoxide using TMSCN under solvent free conditions followed by treatment of the formed trimethylsilyloxy nitrile with pyridine and phosphoryl chloride, afforded the acetylated β-unsaturated nitriles (Z)-4-(2′,3′,4′,6′-tetra-O-β-d-glucopyranosyloxy)but-2-enenitrile and its isomer (E)-4-(2′,3′,4′,6′-tetra-O-β-d-glucopyranosyloxy)but-2-enenitrile. Deacetylation of Z- and/or E-isomers afforded the target molecules alliarinoside and its isomer.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Dense network of OH⋯O and CH⋯O interactions in the solid state
           structure of n-pentyl-2-chloro-2-deoxy-α-d-manno-sept 3-uloside
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Supriya Dey , Krishnayan Basuroy , N. Jayaraman
      Single crystal X-ray structural analysis of a septanoside, namely, n-pentyl-2-chloro-2-deoxy sept-3-uloside (1) provides many finer details of the molecular structure, in addition to its preferred twist-chair conformation, namely, 5,6 TC 3,4 conformation. Structural analysis reveals a dense network of OH⋯O, CH⋯O and van der Waals interactions that stabilize interdigitized, planar bi-layer structure of the crystal lattice.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Self-assembly behavior of tail-to-tail superstructure formed by
           mono-6-O-(4-carbamoylmethoxy-benzoyl)-β-cyclodextrin in solution and
           the solid state
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Zhe Xu , Xin Chen , Jing Liu , Dong-Qing Yan , Chun-Hua Diao , Min-Jie Guo , Zhi Fan
      A novel mono-modified β-cyclodextrin (β-CD) consisting of 4-carbamoylmethoxy-benzoyl unit at the primary side was synthesized and its self-assembly behavior was determined by X-ray crystallography and NMR spectroscopy. The crystal structure shows a ‘Yin-Yang’-like packing mode, in which the modified β-CD exhibits a channel superstructure formed by a tail-to-tail dimer as the repeating motif with the substituted group embedded within the hydrophobic cavity of the facing β-CD. The geometry of the substituted group is determined by the inclusion of the cavity and is further stabilized by two intermolecular hydrogen bonds between the carbonyl O atom and phenyl group. Furthermore, NMR ROESY investigation indicates that the self-assembly behavior of the substituted group within the β-CD cavity is retained in aqueous solution, and the effective binding constant K a was calculated to be 1330M−1 by means of 1H NMR titration according to iterative determination.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Structure and activities of a novel heteroxylan from Cassia obtusifolia
           seeds and its sulfated derivative
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Qifei Cong , Mingsheng Shang , Qun Dong , Wenfeng Liao , Fei Xiao , Kan Ding
      COB1B1S2 was isolated from an alkaline extract of Cassia obtusifolia seeds, and purified by anion-exchange and gel permeation chromatography. It contains arabinose, xylose, and glucuronic acid, in the molar ratio of 5:81:14, with an apparent molecular weight estimated to be 70.4kDa. Elucidated by using chemical and spectroscopic methods, COB1B1S2 was shown to have a backbone consisting of 1,4-linked β-d-Xylp, with one single-unit terminal α-d-GlcpA or α-l-Araf substituted at O-2 for nearly every five 1,4-linked Xylp. COB1B1S2 is structurally different from typical glucuronoxylans by its absence of methylation at O-4 of GlcA. The native COB1B1S2 showed no significant inhibition on the tube formation of human microvascular endothelial cells (HMEC) and on the growth of liver and colon cancer cells. On the contrary, COB1B1S2-Sul, prepared as the sulfated derivative of COB1B1S2, exhibited a significant inhibition on tube formation of HMEC in a dose-dependent manner, and on the growth of Bel7402 liver cancer cells. These results indicated that the introduction of sulfate groups significantly enhanced the biological activity of glucuronoxylan.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • The O-specific polysaccharide of the marine bacterium Rheinheimera
           pacifica KММ 1406T containing d- and
           l-2-acetamido-2-deoxy-galacturonic acids
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Nadezhda A. Komandrova , Maxim S. Kokoulin , Anatoliy I. Kalinovsky , Svetlana V. Tomshich , Lyudmila A. Romanenko , Victor E. Vaskovsky
      The O-specific polysaccharide was isolated from the lipopolysaccharide of Rheinheimera pacifica KММ 1406T and studied by chemical methods along with 1H and 13C NMR spectroscopy. It was shown that the polysaccharide contains one residue each of 2-acetamido-2-deoxy-d-galactose (d-GalNAc), 2-acetamido-2-deoxy-d- and 2-acetamido-2-deoxy-l-galacturonic acids (d-GalNAcA, l-GalNAcA), 2,4-diacetamido-2,4,6-trideoxy-d-glucose (d-QuiNAc4NAc), and 4-(N-acetyl-d-alanyl)amino-4,6-dideoxy-d-glucose (d-Qui4NAlaAc) and has the following structure: →4)-α-d-GalpNAc-(1→4)-α-l-GalpNAcA-(1→3)-β-d-QuipNAc4NAc-(1→2)-β-d-Quip4NDAlaAc-(1→4)-α-d-GalpNAcA-(1→
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • New ureas containing glycosyl and diphenylphosphinyl scaffolds: synthesis
           and the first attempts to use them in asymmetric synthesis
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Stanisław Porwański
      Chiral ureas containing glycosyl and diphenylphosphinyl scaffolds were found to be an effective organocatalyst. They were synthesised in high yields by a one-pot tandem Staudinger/aza-Wittig coupling reaction. The first attempts of using them in asymmetric synthesis are presented. Yields of the Morita–Baylis–Hillman reaction were moderate with an enantiomeric excess of up to 80%.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Structure of a sulfated xylofucan from the brown alga Punctaria
           plantaginea
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Maria I. Bilan , Alexander S. Shashkov , Anatolii I. Usov
      A polysaccharide composed of l-fucose, d-xylose, and sulfate in a molar proportion of about 5:2:3 was isolated from the brown alga Punctaria plantaginea. Polysaccharide structure was elucidated by methylation analysis, Smith degradation, as well as by 1D and 2D NMR spectroscopy. The polysaccharide was shown to contain a backbone of 3-linked α-l-fucopyranose residues, about two thirds of which are sulfated at O-2 forming trisaccharide repeating units →3)-α-l-Fucp2S-(1→3)-α-l-Fucp2S-(1→3)-α-l-Fucp-(1→. This structural regularity is masked by random distribution of non-sulfated β-d-Xylp residues attached to position 4 of the backbone. The polysaccharide is a new representative of a complex ‘fucoidan’ family of sulfated polysaccharides of brown seaweeds.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Assessing acceptor substrate promiscuity of YjiC-mediated glycosylation
           toward flavonoids
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Ramesh Prasad Pandey , Rit Bahadur Gurung , Prakash Parajuli , Niranjan Koirala , Le Thi Tuoi , Jae Kyung Sohng
      The acceptor substrate promiscuity of YjiC, a UDP-glycosyltransferase from Bacillus licheniformis, was explored with seven different classes (flavonols, flavanols, flavones, flavanones, chalcone, stilbene, and isoflavonoids) of 23 flavonoid acceptors. For most of the polyphenols used in the reactions, the enzymatic bioconversion was significantly higher with the production of multiple glucosylated derivatives. This study highlights the highly flexible non-regiospecific glycosylation ability of YjiC toward polyphenolic compounds. The catalytic potential of YjiC could be useful to generate a library of natural product glucosides.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Stereoselective C-glycosidation of d-fucose derivatives directed by the
           protective groups
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Omar Cortezano-Arellano , Camilo A. Meléndez-Becerra , Fernando Cortés , Fernando Sartillo-Piscil , Alejandro Cordero-Vargas
      Stereoselectivity in the C-glycosidation of lactones derived from d-fucose by following Kishi’s method, which involves the addition of a nucleophile onto a carbohydrate-derived lactone and subsequent reduction of the lactol, was found to be reliant on the nature of the C2 and C3 protective groups. Lactones bearing TBDMS protecting groups selectively afford 1,3-trans products (α anomer), in which the stereoselective outcome is in apparent concordance with Woerpel’s model. On the other hand, their benzylated congeners produce the 1,3-cis products (β anomer) as the major diastereoisomers. The latter results suggest an abnormal behavior during the stereoselective nucleophilic substitution at the anomeric position of the benzylated lactones.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Synthesis of chiral dopants based on carbohydrates
    • Abstract: Publication date: 1 July 2014
      Source:Carbohydrate Research, Volume 393
      Author(s): Toru Tsuruta , Tetsuo Koyama , Mikio Yasutake , Ken Hatano , Koji Matsuoka
      Chiral dopants based on carbohydrates for nematic liquid crystals were synthesized from d-glucose, and their helical twisting power (HTP) values were evaluated. The chiral dopants induced helices in the host nematic liquid crystals. An acetyl derivative having an ether-type glycosidic linkage between carbohydrate and a mesogenic moiety showed the highest HTP value of 10.4μm−1, while an acetyl derivative having an anomeric ester-type linkage did not show any HTP. It was surprising that this molecule had no HTP despite the presence of chirality in the molecule. A relationship between HTP and specific rotation was not observed in this study.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Synthesis of hyaluronic acid oligosaccharides and exploration of a
           fluorous-assisted approach
    • Abstract: Publication date: 23 July 2014
      Source:Carbohydrate Research, Volume 394
      Author(s): Giuseppe Macchione , José L. de Paz , Pedro M. Nieto
      The synthesis of hyaluronic acid oligomers (tri- and tetrasaccharide) is described. We have followed a pre-glycosylation oxidation strategy. Glucuronic acid units were directly employed in coupling reactions with suitably protected glucosamine derivatives. In order to simplify the purification of synthetic intermediates, a fluorous-assisted strategy has been also explored. Using this approach, a hyaluronic acid trisaccharide was prepared.
      Graphical abstract image

      PubDate: 2014-06-14T15:16:04Z
       
  • Synthesis of novel 2-deoxy-β-benzyl-C-glycosides by highly stereo-
           and chemoselective hydrogenation of exo-glycals
    • Abstract: Publication date: Available online 21 April 2014
      Source:Carbohydrate Research
      Author(s): Gisela Díaz , Agustín Ponzinibbio , Rodolfo Daniel Bravo
      Novel 2-deoxy-β-benzyl-C-glycosides were prepared in good yields and excellent stereoselectivity by a route involving the Wittig reaction of glycosyl phosphonium salts and reduction of exo-glycals as key steps. Hydrogenation of benzyl protected enol ethers was performed with Pd/C(en) as effective chemoselective catalysts to afford exclusively the β anomers.
      Graphical abstract image Highlights

      PubDate: 2014-04-29T07:17:01Z
       
  • Colourimetric and fluorometric substrates for measurement of pullulanase
           activity
    • Abstract: Publication date: Available online 28 April 2014
      Source:Carbohydrate Research
      Author(s): Barry V. McCleary , David Mangan , Vincent McKie , Claudio Cornaggia , Edward Rooney
      Specific and highly sensitive colourimetric and fluorometric substrate mixtures have been prepared for the measurement of pullulanase and limit-dextrinase activity and assays employing these substrates have been developed. These mixtures comprise thermostable α- and β-glucosidases and either 4,6-O-benzylidene-2-chloro-4-nitrophenyl-β-maltotriosyl (1-6) α-maltotrioside (BzCNPG3G3, 1; Fig. 1) as a colourimetric substrate or 4,6-O-benzylidene-4-methylumbelliferyl-β-maltotriosyl (1-6) α-maltotrioside (BzMUG3G3, 2) as a fluorometric substrate. Hydrolysis of substrates 1 and 2 by exo-acting enzymes such as amyloglucosidase, β-amylase and α-glucosidase is prevented by the presence of the 4,6-O-benzylidene group on the non-reducing end D-glucosyl residue. The substrates are not hydrolysed by any α-amylases studied, (including those from A. niger and porcine pancreas) and are resistant to hydrolysis by Pseudomonas sp. isoamylase. On hydrolysis by pullulanase (Fig. 1), the 2-chloro-4-nitrophenyl-β-maltotrioside (3) or 4-methylumbelliferyl-β-maltotrioside (4) liberated is immediately hydrolysed to D-glucose and 2-chloro-4-nitrophenol or 4-methylumbelliferone. The reaction is terminated by the addition of a weak alkaline solution leading to the formation of phenolate ions in solution whose concentration can be determined using either spectrophotometric or fluorometric analysis. The assay procedure is simple to use, specific, accurate, robust and readily adapted to automation.
      Graphical abstract image Highlights

      PubDate: 2014-04-29T07:17:01Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014