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Carbohydrate Research

Fabien Massicot, Richard Plantier-Royon, Jean-Luc Vasse, Jean-Bernard Behr
Synthetic analogues of the naturally occurring iminosugar homoDMDP, which feature a perfluoroalkyl group at the pseudo-anomeric position, have been synthesized from the corresponding sugar-derived cyclic aldonitrone. The new fluorinated iminosugars as well as homoDMDP and its 6-deoxy counterpart were evaluated for their inhibitory activity against a panel of glycosidases. While the replacement of the (1',2')-dihydroxyethyl substituent of homoDMDP with -C4 F9 proved detrimental for enzyme binding, introduction of a -C3 F7 moiety tuned the inhibitory activity spectrum selectively towards α-fucosidase and α-glucosidase from yeast...
May 15, 2018: Carbohydrate Research
Evelina L Zdorovenko, Alla K Golomidova, Nikolai S Prokhorov, Alexander S Shashkov, Lei Wang, Andrei V Letarov, Yuriy A Knirel
No abstract text is available yet for this article.
May 15, 2018: Carbohydrate Research
Bin Yang, Sof'ya N Senchenkova, Olesya I Naumenko, Alexander S Shashkov, Bin Liu, Andrey V Perepelov, Yuriy A Knirel
An O-specific polysaccharide (O-antigen) was isolated by mild acid degradation of the lipopolysaccharide of Escherichia coli O50 followed by gel chromatography on Sephadex G-50. The following structure of the tetrasaccharide repeat was established by sugar analysis and 1D and 2D 1 H and 13 C NMR spectroscopy: →3)-α-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 3)-β-l-Rhap-(1 → 4)-β-d-GlcpNAc-(1→ The linear O50 polysaccharide has the same structure as the main chain of the branched O polysaccharide of E...
May 7, 2018: Carbohydrate Research
Sae Tanaka, Dušan Kojić, Roumiana Tsenkova, Masato Yasui
Glucose is the most abundant carbohydrate found in living organisms. It exists as two anomers: α-D-glucose and β-D-glucose, which differ in how the hydroxyl group on the C1 carbon is directed. In solutions, the ratio between α- and β-D-glucose is typically 4:6 but can vary depending on the surrounding ions or temperature. In this study, we obtained near-infrared (NIR) spectra of the glucose anomers based on concentration, and analyzed the spectral difference between each anomer by spectra subtraction and principal component analysis, respectively...
May 6, 2018: Carbohydrate Research
Guang Huan Shen, Joon Hee Hong
Nucleoside phosphonates are isosteric, isopolar, and isoelectronic with phosphates. Nucleoside phosphonates can undergo enzymatic phosphorylation for conversion into the corresponding diphosphoryl phosphonates, which are naturally occurring nucleoside triphosphate analogues. The biological activity, which is mostly antiviral and antitumor but sometimes is as specific enzyme inhibitor, is briefly presented to help discover compounds with increased activity over natural nucleosides to provide structure-activity data...
April 28, 2018: Carbohydrate Research
Nitai Sarkar, Richa S Sardessai, Mysore S Shashidhar, Majid I Tamboli, Rajesh G Gonnade
scyllo-Inositol derived 1,2-trans-diequatorial halohydrins can be efficiently converted to the corresponding epoxides in the presence of lithium hydride. The structure of one of the epoxides was determined by single crystal X-ray diffraction analysis. This provides a potential route for the preparation of ring modified inositol derivatives. DFT calculations suggest that this epoxide formation could be proceeding through the intermediacy of the cyclohexane ring-inverted axial-rich conformer (1,2-trans-diaxial halohydrin)...
April 26, 2018: Carbohydrate Research
Evgeny Vinogradov, Frank St Michael, Andrew D Cox
Fusobacterium nucleatum is an anaerobic bacterium found in the human mouth where it causes periodontitis. It was also found in colorectal cancer tissues and is linked with pregnancy complications, including pre-term and still births. Cell surface structures of the bacterium could be implicated in pathogenesis. Here we report the following structure of the lipopolysaccharide O-chain of F. nucleatum strain MJR 7757 B:where Lac is (R)-1-carboxyethyl (lactic acid residue); all monosaccharides are in the pyranose form...
April 25, 2018: Carbohydrate Research
Christian Kjeldsen, Sofie Slott, Pernille L Elverdal, Carmen L Sheppard, Georgia Kapatai, Norman K Fry, Ian C Skovsted, Jens Ø Duus
Streptococcus pneumoniae is characterised into 92 serotypes based on antigenic reactions of commercial rabbit sera to the capsular polysaccharides. During development of a bioinformatic serotyping tool (PneumoCaT), an isolate exhibited a novel codon at residue 385 of the glycosyltransferase gene wcwK encoding a distinct amino acid, which differentiates genogroup 7. Investigation by repeat serotyping and Quellung reaction revealed a novel pattern of factor sera with the isolate reacting very strongly with 7f, but also with 7e factor sera...
April 23, 2018: Carbohydrate Research
Edward S Hems, Sergey A Nepogodiev, Martin Rejzek, Robert A Field
A suite of glycosylated glycerol derivatives representing various fragments of the glycosylated ichthyotoxins called prymnesins were chemically synthesised. Glycerol was used to represent a small fragment of the prymnesin backbone, and was glycosylated at the 2° position with the sugars currently reported to be present on prymnesin toxins. Neighbouring group participation was utilised to synthesise 1,2-trans-glycosides. SnCl2 -promoted glycosylation with furanosyl fluorides gave 1,2-cis-furanosides with moderate stereocontrol, whilst TMSOTf promoted glycosylation with a furanosyl imidate gave a 1,2-cis-furanoside with good stereocontrol...
April 17, 2018: Carbohydrate Research
Jinpeng Wang, Yajing Chang, Xueyang Dong, Renshuai Zhang, Yang Tang, Meng Zhang, Rilei Yu, Tao Jiang, Lijuan Zhang
β-D-xylosides with cytotoxic aglycones have augmented cytotoxicity towards animal cells because β-D-xyloside-primed glycosaminoglycans further enhance the aglycone's cytotoxicity. In this study, we designed and synthesized different 4-anilinequinazoline β-D-xylosides and found that compounds 7-10 possessing 3-chloro-4-((3-fluorobenzyl)oxy)aniline group as in anticancer drug lapatinib also primed glycosaminoglycans and were highly cytotoxic to cancer cells.
April 13, 2018: Carbohydrate Research
Arumugam Sankar, I-Cheng Chen, Shun-Yuan Luo
A simple and efficient protocol for the synthesis of a sphingosine starting from cost-effective phytosphingosine has been described. Two alternative synthetic pathway have been disclosed based on the use of two different kinds of protective groups for the protection of the amino group in the phytosphingosine. The protected phytosphingosine was subsequently transformed into sphingosine in 5 steps i.e. protection of the amine group, protection of 1,3-diol, leaving group insertion, elimination, and one-pot deprotection...
April 13, 2018: Carbohydrate Research
Grégory Legrave, Ramzi Ait Youcef, Damien Afonso, Angélique Ferry, Jacques Uziel, Nadège Lubin-Germain
The synthesis of four C-pyrimidyl nucleosides is described by condensation of small nitrogen molecules (amidines and ureas) onto alkynyl riboside derivatives. These last compounds were obtained by indium mediated stereoselective alkynylation of suitably protected ribose derivatives and the condensation reaction conditions were studied in order to favor the N-attack of the nitrogen molecules leading to the pyrimidine ring formation.
April 13, 2018: Carbohydrate Research
Tchambaga Camara, Abed Bil, Vincent Chagnault
Methyl glyconates have been attracting considerable attention as intermediates for the preparation of aryl C-glycosides, polyphenolic products, aliphatic polyesters, SGLT2 inhibitors, antibiotics etc … In view of the interest in those compounds, we report herein our work on the synthesis of methyl glyconates using an oxidative esterification carried out by molecular iodine. This reaction is catalyzed by non-toxic K4 Fe(CN)6 that releases a small amount of cyanide ion into the reaction mixture. Four benzylated carbohydrates which contain a hemiacetalic functional group have been tested successfully...
April 12, 2018: Carbohydrate Research
Evgeny Vinogradov, Irina Sadovskaya, Pascal Courtin, Saulius Kulakauskas, Thierry Grard, Jennifer Mahony, Douwe van Sinderen, Marie-Pierre Chapot-Chartier
In the lactic acid bacterium Lactococcus lactis, a cell wall polysaccharide (CWPS) is the bacterial receptor of the majority of infecting bacteriophages. The diversity of CWPS structures between strains explains, at least partially, the narrow host range of lactococcal phages. In the present work, we studied the polysaccharide components of the cell wall of the prototype L. lactis subsp. lactis strain IL1403. We identified a rhamnose-rich complex polysaccharide, carrying a glycerophosphate substitution, as the major component...
April 12, 2018: Carbohydrate Research
Olesya I Naumenko, Xi Guo, Sof'ya N Senchenkova, Peng Geng, Andrei V Perepelov, Alexander S Shashkov, Bin Liu, Yuriy A Knirel
Mild acid hydrolysis of the lipopolysaccharide of Escherichia coli O54 afforded an O-polysaccharide, which was studied by sugar analysis, solvolysis with anhydrous trifluoroacetic acid, and 1 H and 13 C NMR spectroscopy. Solvolysis cleaved predominantly the linkage of β-d-Ribf and, to a lesser extent, that of β-d-GlcpNAc, whereas the other linkages, including the linkage of α-l-Rhap, were stable under selected conditions (40 °C, 5 h). The following structure of the O-polysaccharide was established: →4)-α-d-GalpA-(1 → 2)-α-l-Rhap-(1 → 2)-β-d-Ribf-(1 → 4)-β-d-Galp-(1 → 3)-β-d-GlcpNAc-(1→ The O-antigen gene cluster of E...
April 5, 2018: Carbohydrate Research
Ferenc Zsila, Sergey A Samsonov
The anticancer agent ellipticine (ELP) functions as a DNA intercalating drug. Depending on the pH of the medium, it exists both in a neutral and a protonated form. In acidic extracellular microenvironment characteristic to malignant tissues, charged ELP molecules can also bind to glycosaminoglycans (GAGs), linear anionic periodic polysaccharides, which interact with various protein targets affecting diverse cellular events. Although a previous experimental work indicated specific GAG binding of protonated ELP, the underlying molecular mechanisms remain to be elucidated...
April 3, 2018: Carbohydrate Research
Andrzej Nowacki, Beata Liberek
B3LYP and M06-2X optimization and MP2 single point calculations are reported for the4 H5 and5 H4 conformations of 3,4,6-tri-O-acetyl-D-allal, 3,4,6-tri-O-acetyl-D-galactal, 3,4,6-tri-O-acetyl-D-glucal, and 3,4,6-tri-O-acetyl-D-gulal. Significant discrepancies in predictions of relative energies and conformers' population for B3LYP and M06-2X optimized geometries are observed. Generally, B3LYP overestimates the conformers' energies with respect to MP2, whereas M06-2X slightly underestimates the conformers' energies...
March 28, 2018: Carbohydrate Research
Maxim S Kokoulin, Lyudmila A Romanenko, Valery V Mikhailov
The O-polysaccharide was isolated from the lipopolysaccharide of a marine bacterium Simiduia litorea KMM 9504T and studied by chemical methods along with 1D and 2D1 H and13 C NMR spectroscopy including1 H,1 H-TOCSY,1 H,1 H-COSY,1 H,1 H-ROESY,1 H,13 C-HSQC and1 H,13 C-HMBC experiments. The following new structure of the O-polysaccharide of S. litorea KMM 9504T containing D-galacturonamide, 2-acetamido-2,6-dideoxy-D-glucose and 3,6-dideoxy-3-[(R)-2-hydroxypropanoylamino]-D-galactose was established.
March 21, 2018: Carbohydrate Research
Rocío Contreras Sánchez-Matamoros, Antonio M Gil-Serrano, M Rosario Espuny, Francisco Javier Ollero, Manuel Megías, Miguel A Rodríguez-Carvajal
Aeromonas sp. AMG272 is a Gram-negative bacterium that has been isolated from agricultural soil and studied for its plant growth-promoting activities. Structures of the O-specific polysaccharide chain of the AMG272 lipopolysaccharide and its capsular polysaccharide were elucidated using GLC-MS and NMR spectroscopy. The structure of the O-specific polysaccharide, →4)-α-l-Rhap-(1 → 3)-β-d-GlcpNAc-(1→, has been found in other Aeromonas strains and related bacteria, whereas the structure of the capsular polysaccharide has not been reported before: →6)[β-d-Fucp3NAc4Ac-(1 → 3)]-α-d-GlcpNAc-(1 → 4)-α-d-Galp-(1 → 3)-α-d-GalpNAc-(1 → 4)-α-d-Galp-(1 → ...
March 20, 2018: Carbohydrate Research
Yun Kong, Jiang Li, Xinyuan Hu, Yaoguang Wang, Qingyun Meng, Guofeng Gu, Peng George Wang, Min Chen
N-Glycosyltransferase (NGT) is an inverting glycosyltransferase for an unusual pathway of N-linked protein glycosylation and glycosylates polypeptides in the consensus sequon (N-(X≠P)-T/S) with hexose monosaccharides. Here, we expressed and characterized a novel N-glycosyltransferase from Aggregatibacter aphrophilus (named AaNGT). RP-HPLC and Mass Spectrometry were used to assay and quantify glycopeptide formation by AaNGT and determine its substrate specificities. AaNGT could utilize a variety of nucleotide-activated sugar donors, including UDP-Glc, UDP-Gal, UDP-Xyl, GDP-Glc, dGDP-Glc and UDP-GlcN, to glycosylate the tested peptides...
March 19, 2018: Carbohydrate Research
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