Structural elucidation of two polysaccharides present in the lipopolysaccharide of a clinical isolate of Burkholderia cepacia

Based on the sugar composition, methylation analyses and Smith degradation, supported by NMR spectroscopic analyses and fast-atom-bombardment MS experiments, the lipopolysacharide produced by a clinical isolate of Burkholderia cepacia was shown to contain two distinct polymers, both with linear trisaccharide repeating units; a major, containing D-rhamnose and D-galactose residues (2:1) with the structure -->3)-alpha-D-Rhap(1-->3)-alpha-D-Rhap(1-->4)-alpha-D-Galp(1--> (major), and a minor repeating unit, constituted by D-rhamnosyl residues, with the structure -->3)-alpha-D-Rhap(1-->3)-alpha-D-Rhap(1-->2)-alpha-D-Rhap(1--> (minor).