Patent ID: 6284884
Filing Date: 2001-09-04
Classification: A61K,A61P,C08B,Y10S

Abstract:
A process for depolymerizing Group B Streptococcus (GBS) type II and type III polysaccharides to produce fragments having the following 2,5-anhydro-D mannose reducing-end structure, ##STR9##wherein R.sub.1 is H and R.sub.2 is sialylated heptasaccharide repeating-unit of formula ##STR10##wherein n is about 5 to about 50 for the type II, and where R.sub.1 is sialylated pentasaccharide repeating-units of formula ##STR11##wherein n is about 5 to 50 and R.sub.2 is disaccharide .alpha.NeuAc(2-3).beta.-D-Galp1- for the type III,said process comprising the steps ofproviding a GBS type II or GBS type III polysaccharide to be depolymerized and reacting the polysaccharide in an aqueous medium with a base to form a partially de-N-acetylated polysaccharide product, depolymerizing the de-N-acetylated product with a nitrosation agent to form the GBS type II or type III fragments, andrecovering the fragments.