Chemical and n.m.r.-spectroscopic investigation of the capsular polysaccharide of klebsiella serotype k41

The structure of the repeating unit of the capsular polysaccharide from Klebsiella type 41 has been investigated by methylation analysis of the original and the carboxyl-reduced polymer, uronic acid degradation, Smith degradation, and graded acid hydrolysis. Proton- and 13C-n.m.r. spectroscopy of the original polysaccharide and of the fragments obtained by various methods confirmed some structural features and allowed determination of the anomeric configuration of the glycosidic linkages. This polysaccharide is shown to have the following heptasaccharide repeating-unit: ▪ This is the first polysaccharide antigen K of the Klebsiella series found to have seven sugar residues in its repeating unit, and to contain a galactose residue in its furanose form.