Anhydroalditols in the sugar analysis of methanolysates of alditols and oligosaccharide-alditols

Abstract

In the context of the methanolysis procedure for sugar analysis, several alditols were investigated for their capacity to form anhydro derivatives in M methanolic HCl (24 h, 85°). Xylitol, D-arabinitol, L-fucitol, D-glucitol, galactitol, 2-acetamido-2-deoxy-D-galactitol, and the alditols of N-acetylneuraminic acid were very prone to form anhydrides, whereas 2-amino-2-deoxy-D-galactitol, 2-amino-2-deoxy-D-glucitol, D-mannitol, and 2-acetamido-2-deoxy-D-glucitol formed little anhydride. Anhydride formation was observed for the relevant alditols when present in reduced oligosaccharides. This finding is of importance in the quantification of sugar residues based on methanolysis, N-(re)acetylation, trimethylsilylation, and subsequent capillary g.l.c.