Strucrural investigation of Klebsiella serotype K7 polysaccharide

Abstract

Methylation analysis of and partial hydrolysis studies on the Klebsiella K7 capsular polysaccharide and its carboxyl-reduced derivative indicated the recurrence of D-glucopyranuronic acid, D-mannopyranose, and D-glucopyranose residues, linearly linked in a specific manner, in the molecular structure. D-Galactopyranose and pyruvic acid residues are linked to the main chain on the D-mannose residues (at O-3) and the D-glucose residues (at O-4 and O-6), respectively; the simplest interpretation of this evidence is that nine sugar residues and pyruvic acid constitute a repeating unit. The sequence →3)-β- D-GlcA p-(1→2)-α- D-Man p-(1→2)-α- D-Man p-(1→3)- D-Glc p→ was demonstrated by the isolation from the polysaccharide of an aldotetraouronic acid of this structure.