EXOCELLULAR BACTERIAL POLYSACCHARIDE FROM XANTHOMONAS CAMPESTRIS NRRL B-1459: PART I. CONSTITUTION

Abstract

Polysaccharide B-1459 is the first bacterial polysaccharide reported to contain pyruvic acid as a constituent. The polysaccharide, isolated as the potassium salt, was shown to be composed of D-glucose, D-mannose, and D-glucuronic acid, acetic acid, and pyruvic acid in the ratio 2.8:3.0:2.0:1.7:0.51–0.63. One-third of the total mannose was released readily as free mannose by graded acid hydrolysis with only a slow loss of the high solution viscosity. The remainder of the mannose was isolated as the acid-stable aldobiouronic acid 2-O-(β-D-glucopyranosyluronic acid)-D-mannose. Partial acid hydrolysis and preparative paper chromatography afforded two higher oligosaccharides: an aldotriouronic acid composed of glucuronic acid β-linked 1,2 to mannose with glucose as the reducing end group, and what appears to be an aldotetraouronic acid composed of glucuronic acid, mannose, and glucose.