On the phosphate linkages and the structure of a disaccharide unit of the type-specific polysaccharide of pneumococcus type XIX

Abstract

The structure of the capsular polysaccharide (S-XIX) of Pneumococcus Type XIX, which contains residues of d-glucose, l-rhamnose, 2-acetamido-2-deoxy- d-mannose, and phosphate, has been investigated by acid hydrolysis, treatment with acid phosphatase, mass spectrometry, and 13C-n.m.r. spectroscopy. Phosphoric esters in S-XIX were largely resistant to hydrolysis (4 M HCl, 100°, 3 h). With M or 2 M HCl at 100° for 3 h, 4- O-(2-amino-2-deoxy-β- d-mannopyranosyl)- d-glucose 4′-phosphate was liberated. More-drastic hydrolysis of S-XIX gave 2-amino-2-deoxy- d-mannose 3-, 4-, and 6-phosphates, and 4- O-(2-amino-2-deoxy- d-mannopyranosyl)- d-glucose and its 4′-phosphate.