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Yuriy A. Knirel - One of the best experts on this subject based on the ideXlab platform.
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Structure of the O-specific polysaccharide of Azospirillum doebereinerae type strain GSF71T
Carbohydrate Research, 2019Co-Authors: Elena N Sigida, Yuliya P. Fedonenko, Evelina L. Zdorovenko, Svetlana A. Konnova, Alexander S Shashkov, Yuriy A. KnirelAbstract:Abstract O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of plant-growth-promoting rhizobacteria Azospirillum doebereinerae GSF71T and studied by Sugar Analysis along with 1H and 13C NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, and HMBC experiments. It was established that the polysaccharide is linear and consists of tetrasaccharide repeating units with the following structure:
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Structure of the O-polysaccharide of Escherichia coli O60
Russian Chemical Bulletin, 2018Co-Authors: A. V. Perepelov, Alexander S Shashkov, Olesya I. Naumenko, S. N. Senchenkova, Alexander O. Chizhov, Yuriy A. KnirelAbstract:Structure of the O-polysaccharide (O-antigen) of Escherichia coli O60 was studied by Sugar Analysis, partial solvolysis with CF3CO2H, and 1D and 2D 1H and 13C NMR spectroscopy. The O-polysaccharide was found to consist of D-galactose and L-rhamnose. The structure of its branched tetrasaccharide repeating unit was established, which is unique among known bacterial polysaccharide structures.
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Structures of cell-wall glycopolymers of Lactobacillus rhamnosus BIM B-1039.
Carbohydrate Research, 2018Co-Authors: Evelina L. Zdorovenko, Alexander S Shashkov, Alexandra A. Kadykova, Danuta T. Plotnikova, Elena Kiseleva, Galina Novik, Yuriy A. KnirelAbstract:Abstract Glycopolymers of two types were isolated from the cell wall of Lactobacillus rhamnosus BIM B-1039 by stepwise extraction with cold and hot 10% aq CCl3CO2H followed by anion-exchange gel chromatography. The following structures of the glycopolymers were established by Sugar Analysis, Smith degradation and 1D and 2D NMR spectroscopy:
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Structure of the K82 Capsular Polysaccharide from Acinetobacter baumannii LUH5534 Containing a d-Galactose 4,6-Pyruvic Acid Acetal
Biochemistry (Moscow), 2018Co-Authors: A. A. Kasimova, Yuriy A. Knirel, A. S. Shashkov, J. J. Kenyon, N. P. Arbatsky, A. V. Popova, R. M. HallAbstract:Type K82 capsular polysaccharide (CPS) was isolated from Acinetobacter baumannii LUH5534. The structure of a linear tetrasaccharide repeating unit of the CPS was established by Sugar Analysis along with one- and two-dimensional ^1H and ^13C NMR spectroscopy. Proteins encoded by the KL82 capsule gene cluster in the genome of LUH5534 were assigned to roles in the synthesis of the K82 CPS. In particular, functions were assigned to two new glycosyltransferases (Gtr152 and Gtr153) and a novel pyruvyltransferase, Ptr5, responsible for the synthesis of D-galactose 4,6-( R )-pyruvic acid acetal.
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Structure of the O-polysaccharide of Photorhabdus temperata subsp. temperata XlNach T containing a novel branched monosaccharide,
2015Co-Authors: Nikolay P. Arbatsky, Alexander S Shashkov, Nadezhda A. Kirsheva, Anna N. Kondakova, Rima Z. Shaikhutdinova, Sergey A. Ivanov, Andrey P. Anisimov, Yuriy A. KnirelAbstract:O-Polysaccharide was isolated from the lipopolysaccharide of an entomopathogenic bacterium Photorhabdus temperata subsp. temperata XlNach T . Sugar Analysis after full acid hydrolysis of the
Alexander S Shashkov - One of the best experts on this subject based on the ideXlab platform.
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Structure of the O-specific polysaccharide of Azospirillum doebereinerae type strain GSF71T
Carbohydrate Research, 2019Co-Authors: Elena N Sigida, Yuliya P. Fedonenko, Evelina L. Zdorovenko, Svetlana A. Konnova, Alexander S Shashkov, Yuriy A. KnirelAbstract:Abstract O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of plant-growth-promoting rhizobacteria Azospirillum doebereinerae GSF71T and studied by Sugar Analysis along with 1H and 13C NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, and HMBC experiments. It was established that the polysaccharide is linear and consists of tetrasaccharide repeating units with the following structure:
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Structure of the O-polysaccharide of Escherichia coli O60
Russian Chemical Bulletin, 2018Co-Authors: A. V. Perepelov, Alexander S Shashkov, Olesya I. Naumenko, S. N. Senchenkova, Alexander O. Chizhov, Yuriy A. KnirelAbstract:Structure of the O-polysaccharide (O-antigen) of Escherichia coli O60 was studied by Sugar Analysis, partial solvolysis with CF3CO2H, and 1D and 2D 1H and 13C NMR spectroscopy. The O-polysaccharide was found to consist of D-galactose and L-rhamnose. The structure of its branched tetrasaccharide repeating unit was established, which is unique among known bacterial polysaccharide structures.
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Structures of cell-wall glycopolymers of Lactobacillus rhamnosus BIM B-1039.
Carbohydrate Research, 2018Co-Authors: Evelina L. Zdorovenko, Alexander S Shashkov, Alexandra A. Kadykova, Danuta T. Plotnikova, Elena Kiseleva, Galina Novik, Yuriy A. KnirelAbstract:Abstract Glycopolymers of two types were isolated from the cell wall of Lactobacillus rhamnosus BIM B-1039 by stepwise extraction with cold and hot 10% aq CCl3CO2H followed by anion-exchange gel chromatography. The following structures of the glycopolymers were established by Sugar Analysis, Smith degradation and 1D and 2D NMR spectroscopy:
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Structure of the O-polysaccharide of Photorhabdus temperata subsp. temperata XlNach T containing a novel branched monosaccharide,
2015Co-Authors: Nikolay P. Arbatsky, Alexander S Shashkov, Nadezhda A. Kirsheva, Anna N. Kondakova, Rima Z. Shaikhutdinova, Sergey A. Ivanov, Andrey P. Anisimov, Yuriy A. KnirelAbstract:O-Polysaccharide was isolated from the lipopolysaccharide of an entomopathogenic bacterium Photorhabdus temperata subsp. temperata XlNach T . Sugar Analysis after full acid hydrolysis of the
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structure and gene cluster organization of the o antigen of providencia alcalifaciens o45 h25
Carbohydrate Research, 2014Co-Authors: Olga G Ovchinnikova, Alexander S Shashkov, Magdalena Moryl, Antoni Rozalski, Yuriy A. KnirelAbstract:Abstract 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: Download : Download full-size image The O-antigen gene cluster of P. alcalifaciens O45 was sequenced and found to be in full agreement with the O-polysaccharide structure established.
Gaëlle Daniele - One of the best experts on this subject based on the ideXlab platform.
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Combination of Sugar Analysis and stable isotope ratio mass spectrometry to detect the use of artificial Sugars in royal jelly production.
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Marine Wytrychowski, Hervé Casabianca, Gaëlle DanieleAbstract:The effects of feeding bees artificial Sugars and/or proteins on the Sugar compositions and (13)C isotopic measurements of royal jellies (RJs) were evaluated. The Sugars fed to the bees were two C4 Sugars (cane Sugar and maize hydrolysate), two C3 Sugars (Sugar beet, cereal starch hydrolysate), and honey. The proteins fed to them were pollen, soybean, and yeast powder proteins. To evaluate the influence of the Sugar and/or protein feeding over time, samples were collected during six consecutive harvests. (13)C isotopic ratio measurements of natural RJs gave values of around -25 ‰, which were also seen for RJs obtained when the bees were fed honey or C3 Sugars. However, the RJs obtained when the bees were fed cane Sugar or corn hydrolysate (regardless of whether they were also fed proteins) gave values of up to -17 ‰. Sugar content Analysis revealed that the composition of maltose, maltotriose, sucrose, and erlose varied significantly over time in accordance with the composition of the syrup fed to the bees. When corn and cereal starch hydrolysates were fed to the bees, the maltose and maltotriose contents of the RJs increased up to 5.0 and 1.3 %, respectively, compared to the levels seen in authentic samples (i.e., samples obtained when the bees were fed natural food: honey and pollen) that were inferior to 0.2% and not detected, respectively. The sucrose and erlose contents of natural RJs were around 0.2 %, whereas those in RJs obtained when the bees were fed cane or beet Sugar were as much as 4.0 and 1.3 %, respectively. The combination of Sugar Analysis and (13)C isotopic ratio measurements represents a very efficient analytical methodology for detecting (from early harvests onward) the use of C4 and C3 artificial Sugars in the production of RJ.
Feng Xu - One of the best experts on this subject based on the ideXlab platform.
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structural characterization of hemicelluloses fractionated by graded ethanol precipitation from pinus yunnanensis
Carbohydrate Research, 2012Co-Authors: Feng XuAbstract:Abstract Fractionation of hemicelluloses from delignified Pinus yunnanensis was carried out with KOH/H3BO3 solution followed by graded precipitation in 15%, 60%, and 90% (v/v) ethanol solutions, respectively. Chemical compositions, physicochemical properties, and structures of the precipitated hemicellulosic fractions were elucidated by a combination of Sugar Analysis, GPC, FT-IR, and 1H, 13C and 2D HSQC NMR spectroscopy. Sugar Analysis showed that the hemicellulosic fraction precipitated by 15% ethanol solution (H1) had a predominance of xylose (58.52%), while mannose was the major Sugar component in the hemicellulosic fractions precipitated by 60% (H2) and 90% (H3) ethanol solutions. GPC results revealed that the hemicelluloses precipitated by low concentration of ethanol solutions had higher weight-average molecular mass (50,090–79,840 g/mol) than those obtained in the high concentration of ethanol solutions (16,500 g/mol). The fraction precipitated by 60% ethanol solution (H2) was composed of d -galactose, d -glucose and d -mannose in a ratio of approximately 1:1:3.5. Structural determination indicated that the hemicellulosic fraction (H2) had a main structure of (1→4)-linked β-glucomannans backbone with (1→6)-linked α- d -galactose as a side chain attached to C-6 of mannose units. In addition, this fraction also contained minor amounts of xylans.
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pretreatment of partially delignified hybrid poplar for biofuels production characterization of organosolv hemicelluloses
Industrial Crops and Products, 2011Co-Authors: Xueming Zhang, Lingyan Meng, Feng XuAbstract:Abstract In this study, extraction of hemicelluloses from the carbohydrate-enriched residues was successfully carried out with organic solvent and the residue was used for bio-based energy production. The chemical composition and physico-chemical properties of six hemicelluloses released were elucidated by a combination of Sugar Analysis, molecular determination, Fourier transform infrared, and 1H, 13C and 2D-HSQC NMR spectroscopy. The results showed that the successful treatments resulted in a fractionation of the native hemicelluloses. The Sugar Analysis indicated that xylose (47.14–56.91%) was found to be the major Sugar components and small amounts of glucose (14.1–19.06%) and mannose (12.41–18.09%) were also observed in these hemicellulosic fractions. Further studies by NMR spectroscopy exhibited that the acetylated hemicellulosic fraction had a main structure of (1 → 4)-linked β- d -xylopyranosyl backbone with 4-O-methyl-α- d -glucuronic acid as a side chain and a minor structure of linear β-(1 → 4)-linked glucomannans. Furthermore, these hemicelluloses possessed a low substituted degree which was beneficial for enzymatic saccharification.
Hayao Tanoue - One of the best experts on this subject based on the ideXlab platform.
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degradation of cell wall materials from sweetpotato cassava and potato by a bacterial protopectinase and terminal Sugar Analysis of the resulting solubilized products
Journal of Bioscience and Bioengineering, 2002Co-Authors: Lorena D Salvado, Toshihiko Suganuma, Kanefumi Kitahara, Yoshihito Fukushige, Hayao TanoueAbstract:Cell wall materials (CWMs) from sweetpotato, cassava, and potato starch residues were degraded using a crude enzyme solution from the culture filtrate of a Bacillus sp. isolated from soil, Bacillus sp. M4. This organism has been found to secrete polygalacturonic acid lyase (PGL) and glycan depolymerase activities, especially arabinanase, but cellulase activity was nearly absent. Sugar Analysis of the solubilized product after enzyme treatment at pH 7.0 revealed that it is mainly composed of galacturonic acid, galactose, and arabinose, the Sugars found commonly in the pectin fraction. This suggested the presence of a protopectinase (PPase) activity in the culture filtrate. The presence of EDTA completely inhibited PGL but PPase activity was almost retained, suggesting that the PGL is not the primary activity responsible for pectin solubilization. The mode of action of the crude enzyme was determined by terminal Sugar Analysis using HPAEC-PAD after hydrolysis of the reduced products. Results revealed that galactose is the main neutral Sugar at the reducing terminal of the products, although rhamnose was also present in the higher molecular weight component. This suggested that at neutral pH, the primary activity in the culture filtrate of Bacillus sp. M4 is a B-type PPase, which attacked the galactan as well as rhamnogalacturonan moieties of the protopectin, resulting in the release of a soluble pectin fraction.
