SYNTHESIS OF COMPLEX CARBOHYDRATES

摘要

A tailor-assembly approach is employed for synthesis of complex carbohydrates wherein a polysaccharide is degraded and the shorter product obtained from the degradation is subjected to enzymatic modification to add a sugar moiety. The products may be useful in the preparation of a cancer vaccine. In one example, oligosaccharides of the type Ia group B Streptococcus (GBSIa) capsular polysaccharide and multivalent sialyl Leantigens are specifically described. GBSIa polysaccharide was depolymerized by partial Smith degradation to fragments representing asialo core repeating units. Enzymatic sialylation of these oligomers furnished GBSIa repeating units (from monomer to pentamer). Fucosylation on GlcNAc residues of GBSIa oligomers afforded oligosaccharides that carry multiple sialyl Leepitopes.