Structure of the capsular polysaccharide of Klebsiella serotype K50

Abstract

The structure of the capsular polysaccharide from Klebsiella K50 has been determined by using the techniques of methylation, periodate oxidation, partial hydrolysis, and β-elimination. N.m.r. spectroscopy ( 1H and 13C) was used to establish the nature of the anomeric linkages. The polysaccharide is comprised of repeating units of the heptasaccharide shown and is one of 19 capsular polysaccharides that are composed of d-glucuronic acid, d-galactose, d-glucose, and d-mannose residues, this is one. It has the only known, “five-plus-two”, repeating unit; the structure of the polysaccharide from Klebsiella K50 is, therefore, unique in this series.