Modification of polysaccharides containing uronic acid residues

Klebsiella Type 47 capsular polysaccharide has side chains attached to the main chain via D-glucuronic acid residues. The side chains have been removed to yield an essentially linear polysaccharide by the following sequence of reactions: (1) substitution of hydroxyl and carboxyl groups with methyl vinyl ether; (2) beta-elimination by treatment with base; (3) removal of modified uronic acid residues and protecting groups by mild acid hydrolysis. The possibility of modifying other uronic acid-containing polysaccharides by this method is discussed.