Structural studies of the capsular polysaccharide elaborated by Haemophilus influenza type d

The structure of the capsular polysaccharide elaborated by Haemophilus influenzae type d has been investigated, methylation analysis and n.m.r. spectrometry being the principal methods used. It is concluded that the polysaccharide is composed of repeating units having the structure: leads to 4)-beta-D-GlcpNAc-(1 leads to 3)-beta-D-ManpNAcA-(1 leads to. In addition, single residues of L-alanine, L-serine, or L-threonine, in the proportions 2:2:1, are linked, through their amino groups, to C-6 of the 2-acetamido-2-deoxy-beta-D-mannopyranosyluronic acid residues. The degree of substitution (75-85%) varies for different preparations.