Structural studies of two capsular polysaccharides elaborated by different strains of Haemophilus influenzae type e

The structures of two capsular polysaccharides elaborated by Haemophilus influenzae type e, strains NCTC 8455 and 8472, respectively, have been investigated, methylation analysis and n.m.r. spectrometry being the principal methods used. It is concluded that the polysaccharides are composed of repeating-units having the following structure: Formula: [See Text]. In the polysaccharide from strain NCTC 8472, all of the repeating-units contain the beta-D-fructofuranosyl group. The polysaccharide from strain NCTC 8455, however, contains only traces of D-fructose, corresponding to approximately one group per 100 repeating-units.