The selective cleavage of glycopyranosiduronamide linkages in methylated polysaccharides

Hofmann degradation of glycosiduronamide linkages in methylated polysaccharides furnishes pentodialdose derivatives to which any sugar residues external to uronic acid residues remain attached together with degraded methylated polysaccharides carrying aglyconic hydroxyl groups. The selective degradation has been carried out on methylated derivatives of birch xylan, gum arabic, and the capsular polysaccharide from Klebsiella type 47. Procedures for the degradation of methylated polysaccharides in the vicinity of uronic acid residues are assessed.