title: Structure of repeating units of a polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense SR80.
abstract: A high-molecular mass polysaccharide fraction was obtained by mild acid hydrolysis of the lipopolysaccharide of diazotrophic rhizobacterium Azospirillum brasilense SR80 followed by GPC on Sephadex G-50 Superfine. Studies by composition and methylation analyses, Smith degradation, and 1D and 2D (1)H and (13)C NMR spectroscopy demonstrated the presence of two structurally distinct repeating units having the following structures: It seems likely, although not proved, that these are repeats of two distinct polysaccharides rather than they build blocks within the same polysaccharide chain. The former structure is new, whereas the latter is closely related to the O-polysaccharide structure of A. brasilense Jm6B2 established earlier, which differs in partial (~60%) 3-O-methylation of d-rhamnose only [Boiko, A. S.; Dmitrenok, A. S.; Fedonenko, Yu. P.; Zdorovenko, E. L.; Konnova, S. A.; Knirel, Y. A.; Ignatov, V. V. Carbohydr. Res.2012, 355, 92-95].
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia.
authors.forename: Elena N
authors.initials: EN
authors.lastname: Sigida
authors.forename: Yuliya P
authors.initials: YP
authors.lastname: Fedonenko
authors.forename: Evelina L
authors.initials: EL
authors.lastname: Zdorovenko
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Konnova
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Ignatov
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D015806:Azospirillum brasilense / Q000737:chemistry*; D002240:Carbohydrate Sequence; D006868:Hydrolysis; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry*; D012210:Rhamnose / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D019081:O Antigens; D012210:Rhamnose