- Structure and gene cluster of the O-antigen of Escherichia coli O102
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The O-polysaccharide (O-antigen) of Escherichia coli O102 was studied by sugar analysis along with one- and two-dimensional 1H and 13C NMR spectroscopy. The following structure of the branched pentasaccharide repeating unit was estab
- Perepelov, Andrei V.,Senchenkova, Sof'Ya N.,Shashkov, Alexander S.,Knirel, Yuriy A.,Wang, Quan,Gong, Yanping,Wang, Lei
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p. 73 - 77,5
(2012/12/13)
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- Heterogeneous structure of O-antigenic part of lipopolysaccharide of Salmonella telaviv (Serogroup O:28) containing 3-acetamido-3,6-dideoxy-D- glucopyranose
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The O-polysaccharide of Salmonella Telaviv was obtained by mild acid degradation of the lipopolysaccharide and studied by chemical methods (sugar and methylation analyses, Smith degradation, de-O-acetylation) and NMR spectroscopy. The structure of the O-polysaccharide was established. The repeating units that are proximal to the lipopolysaccharide core region mostly have a digalactose side chain and lack glucose, whereas those at the other end of the chain mostly do bear glucose but are devoid of the disaccharide side chain. This is the first structure established for the O-polysaccharide of a Salmonella serogroup O:28 (formerly M) strain characterized by subfactors O281 and O282. Knowledge of this structure and the structure of the O-polysaccharide of Salmonella Dakar (O281, O28 3) established earlier is crucial for determination of the exact structures associated with subfactors O281, O282, and O283 and elucidation of the genetic basis of the close relationship between Escherichia coli O71 and S. enterica O:28 O-antigens.
- Kumirska,Dziadziuszko,Czerwicka,Lubecka,Kunikowska,Siedlecka,Stepnowski
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experimental part
p. 780 - 790
(2012/01/19)
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- High-throughput determination of urinary hexosamines for diagnosis of mucopolysaccharidoses by capillary electrophoresis and high-performance liquid chromatography
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Mucopolysaccharidoses (MPS) diagnosis is often delayed and irreversible organ damage can occur, making possible therapies less effective. This highlights the importance of early and accurate diagnosis. A high-throughput procedure for the simultaneous determination of glucosamine and galactosamine produced from urinary galactosaminoglycans and glucosaminoglycans by capillary electrophoresis (CE) and HPLC has been performed and validated in subjects affected by various MPS including their mild and severe forms, Hurler and Hurler-Scheie, Hunter, Sanfilippo, Morquio, and Maroteaux-Lamy. Contrary to other analytical approaches, the present single analytical procedure, which is able to measure total abnormal amounts of urinary GAGs, high molecular mass, and related fragments, as well as specific hexosamines belonging to a group of GAGs, would be useful for possible application in their early diagnosis. After a rapid urine pretreatment, free hexosamines are generated by acidic hydrolysis, derivatized with 2-aminobenzoic acid and separated by CE/UV in ~10 min and reverse-phase (RP)-HPLC in fluorescence in ~21 min. The total content of hexosamines was found to be indicative of abnormal urinary excretion of GAGs in patients compared to the controls, and the galactosamine/glucosamine ratio was observed to be related to specific MPS syndromes in regard to both their mild and severe forms. As a consequence, important correlations between analytical response and clinical diagnosis and the severity of the disorders were observed. Furthermore, we can assume that the severity of the syndrome may be ascribed to the quantity of total GAGs, as high-molecular-mass polymers and fragments, accumulated in cells and directly excreted in the urine. Finally, due to the high-throughput nature of this approach and to the equipment commonly available in laboratories, this method is suitable for newborn screening in preventive public health programs for early detection of MPS disorders, diagnosis, and their treatment.
- Coppa, Giovanni V.,Galeotti, Fabio,Zampini, Lucia,MacCari, Francesca,Galeazzi, Tiziana,Padelia, Lucia,Santoro, Lucia,Gabrielli, Orazio,Volpi, Nicola
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scheme or table
p. 32 - 42
(2012/01/13)
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- Structure of the O-antigen of Acinetobacter lwoffii EK30A; Identification of d-homoserine, a novel non-sugar component of bacterial polysaccharides
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We established a peculiar structure of the O-specific polysaccharide (O-antigen) of a psychrotrophic strain of Acinetobacter lwoffii, EK30A, isolated from a 1.6-1.8 million-year-old Siberian permafrost subsoil sediment sample. The polysaccharide was released by mild acid degradation of the lipopolysaccharide and studied using chemical analyses, Smith degradation, 1H and 13C NMR spectroscopy and mass spectrometry. It was found to contain d-homoserine, which is N-linked to 4-amino-4,6-dideoxy-d- glucose (Qui4N) and is N-acylated itself with acetyl in about half of the repeating units or (S)-3-hydroxybutanoyl group in the other half. The following is the structure of the tetrasaccharide repeating unit of the polysaccharide: →3)-β-d-Quip4NAcyl-(1→6)-α-d-Galp-(1→4) -α-d-GalpNAc-(1→3)-α-d-FucpNAc-(1→ where Acyl stands for either N-acetyl- or N-[(S)-3-hydroxybutanoyl]-d-homoseryl. The Royal Society of Chemistry 2010.
- Arbatsky, Nikolay P.,Kondakova, Anna N.,Shashkov, Alexander S.,Drutskaya, Marina S.,Belousov, Pavel V.,Nedospasov, Sergei A.,Petrova, Mayya A.,Knirel, Yuriy A.
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experimental part
p. 3571 - 3577
(2010/08/21)
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- Process for the preparation of cyclopropane carboxylic acid esters
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3-(Halogenovinyl- or propenyl-)-2,2-dimethyl cyclopropane-1-carboxylic acid esters, which are precursors of, or may themselves be, pyrethroid insecticides, are prepared by the reaction of certain halogenopentadienes with an alkyl diazoacetate in the presence of a catalyst which is a transition metal complex of certain chiral Schiff bases, which catalysts tend to increase the yield of preferred cis IR isomer relative to the other possible isomers.
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