title: The O-polysaccharide of Escherichia coli O112ac has the same structure as that of Shigella dysenteriae type 2 but is devoid of O-acetylation: a revision of the S. dysenteriae type 2 O-polysaccharide structure.
abstract: The O-antigen structure of Shigella dysenteriae type 2 was reinvestigated using chemical modifications along with high-resolution 2D (1)H and (13)C NMR spectroscopy. The O-antigen was found to contain a pyruvic acid acetal, which was overlooked in an early study, and the following revised structure of the pentasaccharide repeating unit was established: where approximately 70% GlcNAc residues bear an O-acetyl group at position 3. The O-antigen of Escherichia coli O112ac was found to have the same carbohydrate structure but to lack O-acetylation.
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation. perepel@ioc.ac.ru
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Perepelov
authors.forename: Andrej
authors.initials: A
authors.lastname: Weintraub
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Sof'ya N
authors.initials: SN
authors.lastname: Senchenkova
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Göran
authors.initials: G
authors.lastname: Widmalm
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D002240:Carbohydrate Sequence; D002849:Chromatography, Gas; D004926:Escherichia coli / Q000737:chemistry*; D006868:Hydrolysis; D008070:Lipopolysaccharides / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis; D019081:O Antigens / Q000737:chemistry* / Q000302:isolation & purification; D011773:Pyruvates / Q000032:analysis; D012762:Shigella dysenteriae / Q000737:chemistry*; D014269:Trifluoroacetic Acid / Q000032:analysis / Q000737:chemistry
chemical_list: D008070:Lipopolysaccharides; D009005:Monosaccharides; D019081:O Antigens; D011773:Pyruvates; C064986:pyruvic acid acetal; D014269:Trifluoroacetic Acid