Construction of multivalent sialyl Le(x) from the type Ia group B Streptococcus capsular polysaccharide.

The type Ia group B Streptococcus (GBSIa) capsular polysaccharide was specifically degraded by partial Smith oxidation of 2,3-diol of the Glc in the backbone to fragments representing asialo core repeating units. Sialylation of these oligomers furnished GBSIa multiple repeating units. One, two and three repeating units of GBSIa were obtained pure, and the higher oligomers were obtained as mixtures. After enzymatic fucosylation oligosaccharides carrying bivalent, trivalent and other multivalent sialyl Le(x) epitopes presented as appendages on an oligolactoside scaffold were obtained.