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

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 (4M HCl, 100 degrees, 3 h). With M or 2M HCl at 100 degrees for 3 h, 4-O-(2-amino-2-deoxy-beta-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.