title: Structures of the O4 and O18 antigens of Stenotrophomonas maltophilia: a case of enantiomeric repeating units.
abstract: The O-specific side-chain polymers of lipopolysaccharides from the reference strains for Stenotrophomonas maltophilia serogroups 04 and O18 are both xylosylated rhamnans. In the 04 polymer, both sugar components are the D isomers, whereas the O18 polymer contains only the L isomers. By means of NMR spectroscopy, methylation analysis and Smith degradation, the repeating unit of the 04 polymer was identified as a doubly-branched pentasaccharide of the structure shown below. The O18 polymer is based on the enantiomeric pentasaccharide, but the xylosyl substituent at the 4-position is apparently absent from some units. The polymers closely resemble the O antigens found in Xanthomonas campestris pathovars. [structure: see text]
authors.affiliation: Department of Chemistry, Faculty of Science and the Environment, University of Hull, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Winn
authors.forename: S G
authors.initials: SG
authors.lastname: Wilkinson
mesh_terms: D000942:Antigens, Bacterial / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry*; D020615:Stenotrophomonas maltophilia / Q000737:chemistry* / Q000276:immunology; D013237:Stereoisomerism
chemical_list: D000942:Antigens, Bacterial; D008070:Lipopolysaccharides; D019081:O Antigens; C430945:O18 antigen, Stenotrophomonas; C430944:O4 antigen, Stenotrophomonas