Structure of the 3-deoxy-D-manno-octulosonic acid-(KDO)-containing capsular polysaccharide (K14 antigen) from Escherichia coli 06:K14:H31.

The chemical structure of the K14-antigenic polysaccharide (K14 antigen) of Escherichia coli 06:K14:H31 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation, and study of the oligosaccharides obtained by partial hydrolysis. The polysaccharide consists of [O-(2-acetamido-2-deoxy-beta-D-galactopyranosyl)-(1 leads to 5)-O-(3-deoxy-beta-D-manno-octulopyranosylonic acid)-(2 leads to 6)] repeating units, approximately 60% of the octonic acid units being O-acetylated and approximately 10% O-propionylated at O-8. The sequence of acetylated and propionylated residues is not known. The serologically-specific part of the K14 antigen residues in the polysaccharide part.