title: Characterization of the exopolysaccharide produced by Streptococcus thermophilus 8S containing an open chain nononic acid.
abstract: The exopolysaccharide produced by Streptococcus thermophilus 8S in reconstituted skimmed milk is a heteropolysaccharide containing d-galactose, d-glucose, d-ribose, and N-acetyl-d-galactosamine in a molar ratio of 2 : 1 : 1 : 1. Furthermore, the polysaccharide contains one equivalent of a novel open chain nononic acid constituent, 3,9-dideoxy-d-threo-d-altro-nononic acid, ether-linked via C-2 to C-6 of an additional d-glucose per repeating unit. Methylation analysis and 1D/2D NMR studies (1H and 13C) performed on the native polysaccharide, and mass spectrometric and NMR analyses of the oligosaccharide obtained from the polysaccharide by de-N-acetylation followed by deamination and reduction demonstrated the 'hepta'saccharide repeating unit to be: -->4)-alpha-D-Galp-(1-->2)-beta-D-Ribf-(1-->4)-beta-D-Galp-(1-->4)-beta-D-Glcp-(1--7')-Sub-(1-->4)-beta-D-GalpNAc-(1--> in which Sug is 6-O-(3',9'-dideoxy-d-threo-d-altro-nononic acid-2'-yl)-alpha-d-glucopyranose.
authors.affiliation: Bijvoet Center, Department of Bio-Organic Chemistry, Section of Glycoscience and Biocatalysis, Utrecht University, Utrecht, the Netherlands.
authors.forename: Elisabeth J
authors.initials: EJ
authors.lastname: Faber
authors.forename: Daan J
authors.initials: DJ
authors.lastname: Van Haaster
authors.forename: Johannis P
authors.initials: JP
authors.lastname: Kamerling
authors.forename: Johannes F G
authors.initials: JF
authors.lastname: Vliegenthart
mesh_terms: D002240:Carbohydrate Sequence; D002849:Chromatography, Gas; D019344:Lactic Acid / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008745:Methylation; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D013291:Streptococcus / Q000737:chemistry*; D013400:Sugar Acids / Q000737:chemistry
chemical_list: D009005:Monosaccharides; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D013400:Sugar Acids; D019344:Lactic Acid