title: Synthesis of di- to penta-saccharides related to the O-specific polysaccharide of Shigella dysenteriae type 1, and their nuclear magnetic resonance study.
abstract: The syntheses of oligosaccharide fragments of the O-specific polysaccharide of the lipopolysaccharide of Shigella dysenteriae type 1 are described, including disaccharides methyl O-alpha-D-mannopyranosyl-(1-->2)-alpha-D-galactopyranoside (1), and methyl O-(2-deoxy-2-propionamido-alpha-D-glucopyranosyl)-(1-->3)-alpha-L- rhamnopyranoside (2), trisaccharide methyl O-alpha-D-galactopyranosyl-(1-->3)-O-(2-acetamido-2-deoxy-alpha-D- glucopyranosyl)-(1-->3)-alpha-L-rhamnopyranoside (3), tetrasaccharide methyl O-alpha-L-rhamnopyranosyl-(1-->2)-O-alpha-D-galactopyranosyl-(1-->3)- O-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-(1-->3)-alpha-L-rhamno -pyranoside (4), and pentasaccharide methyl O-alpha-L-rhamnopyranosyl-(1-->3)-O-alpha-L- rhamnopyranosyl-(1-->2)-O-alpha-D-galactopyranosyl- (1-->3)-O-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-(1-->3)-alpha-L- rhamnopyranoside (5). The following monosaccharide building blocks were used as starting compounds: methyl 6-O-tert-butyldiphenylsilyl-3,4-O-isopropylidene-alpha-D-galact opy ranoside (8), methyl 3,4,6-tri-O-benzyl-2-O-(4-methoxybenzyl)-1-thio-beta-D- galactopyranoside (11), methyl 3,4,6-tri-O-acetyl-2-azido-2-deoxy-1-thio-alpha- D-glucopyranoside (16), methyl 2-azido-4,6-O-benzylidene-2-deoxy-1-thio-alpha-D- glucopyranoside (18), methyl 2,4-di-O-benzyl-alpha-L-rhamnopyranoside (21), methyl 2,3,4-tri-O-benzoyl-1-thio-alpha-L-rhamnopyranoside (22), 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl bromide (23), and methyl 4-O-benzyl-alpha-L-rhamnopyranoside (24). Nuclear magnetic resonance data indicate that oligosaccharides 4 and 5 partially mimic the conformation of the O-specific polysaccharide of S. dys. type 1.
authors.affiliation: Laboratory of Developmental and Molecular Immunity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
authors.forename: V
authors.initials: V
authors.lastname: Pozsgay
authors.forename: B
authors.initials: B
authors.lastname: Coxon
authors.forename: H
authors.initials: H
authors.lastname: Yeh
mesh_terms: D000942:Antigens, Bacterial / Q000737:chemistry*; D001428:Bacterial Vaccines / Q000138:chemical synthesis; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004405:Dysentery, Bacillary / Q000517:prevention & control; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D019081:O Antigens; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000276:immunology; D012762:Shigella dysenteriae / Q000737:chemistry* / Q000145:classification / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D019081:O Antigens; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial