Structural elucidation of the capsular polysaccharide of Streptococcus pneumoniae type 9N

The specific capsular polysaccharide of Streptococcus pneumoniae type 9N (American type 9) contains D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-mannose in the molar ratio of 2:1:1:1. Accumulated data from spectroscopic (13C and 1H nuclear magnetic resonance) and methylation analyses of the native and specifically degraded polysaccharide indicated that it was linear and composed of the following pentasaccharide repeating unit; -4)-alpha-D-GlcpA-(1 leads to 3)-alpha-D-Glcp-(1 leads to 3)-beta-D-ManpNAc-(1 leads to 4)-alpha-D-Glcp-(1 leads to 4)-beta-D -GlcpNAc(1 leads to. Structural regions in the type 9N polysaccharide common to those of types 9A, 9L, and 9V have been identified which account for the cross-reactivity of this groups of polysaccharides.