title: Structural determination of the capsular polysaccharide of Streptococcus pneumoniae type 19A (57).
abstract: The structure of the Pneumococcus type 19A (57) capsular polysaccharide has been reinvestigated by using methylation analysis and n.m.r. spectroscopy. It is composed of residues of 2-acetamido-2-deoxy-D-mannose, D-glucose, L-rhamnose, and phosphate in the molar ratios of 1:1:1:1. The polysaccharide is linear, and is composed of these components in a repeating unit of the following structure. ---- 4)-beta-D-ManpNAc-(1 ---- 4)-alpha-D-Glcp-(1 ---- 3)-alpha-L- Rhap-(1-PO4-) ---- The type 19A polysaccharide (Na+ salt) was depolymerized by heating it in water at 100 degrees, conditions that also hydrolyzed the newly formed phosphoric monoesters.
mesh_terms: D002240:Carbohydrate Sequence; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D013296:Streptococcus pneumoniae / Q000032:analysis*
chemical_list: D011135:Polysaccharides, Bacterial