title: Synthesis of di- and tri-saccharides related to the polysaccharide from Streptococcus pneumoniae type 23 and a study of their inhibition in the precipitin reaction.
abstract: Syntheses of methyl 2-O-beta-L-rhamnopyranosyl-beta-D-galactopyranoside (9), methyl 2-O-alpha-L-rhamnopyranosyl-beta-D-galactopyranoside (13), and methyl 4-O-beta-D-glucopyranosyl-2-O-alpha-L-rhamnopyranosyl-beta-D- galactopyranoside (16) in good yields are described. Both 13 and 16 significantly inhibit antigen-antibody precipitation in the S. pneumoniae Type 23 immune system. The results indicate that the rhamnosyl group in the side chain of the repeating unit of the antigen is alpha and not beta as reported previously, and that the trisaccharide related to 16 is the immunodominant group.
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Calcutta.
authors.forename: A K
authors.initials: AK
authors.lastname: Ray
authors.forename: U B
authors.initials: UB
authors.lastname: Maddali
authors.forename: A
authors.initials: A
authors.lastname: Roy
authors.forename: N
authors.initials: N
authors.lastname: Roy
mesh_terms: D000937:Antigen-Antibody Reactions; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis* / Q000276:immunology; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000138:chemical synthesis* / Q000276:immunology; D011233:Precipitin Tests; D013296:Streptococcus pneumoniae / Q000276:immunology*; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000276:immunology
chemical_list: D004187:Disaccharides; D011135:Polysaccharides, Bacterial; D014312:Trisaccharides; C064411:methyl 2-O-beta-rhamnopyranosyl-beta-galactopyranoside; C064410:methyl 2-O-alpha-rhamnopyranosyl-beta-galactopyranoside; C064412:methyl 4-O-beta-glucopyranosyl-2-O-alpha-rhamnopyranosyl-beta-galactopyranoside