Analysis of anomeric configurations in glyceroglycolipids and glycosphingolipids by chromium trioxide oxidation

Acetylation and CrO(3) oxidation in acetic acid (Angyal and James, Aust. J. Chem. 23: 1209-1221, 1970) was applied to 18 different glyceroglycolipids and glycosphingolipids of known structure. The lipids studied contained from one to five pyranosic monosaccharide units including alpha- and beta-linked glucose, galactose, mannose, and N-acetylgalactosamine and beta-linked N-acetylglucosamine. Monosaccharides bound to the lipids through beta-glycosidic linkages reacted to the extent of 80-97 percent, but in the case of alpha-glycosidic linkages the oxidation proceeded only to the extent of 0-6 percent. A partial reaction was observed in lipids in which a given monosaccharide unit was present in both anomeric forms. Therefore, oxidation with CrO(3) allows the determination of anomeric configurations in simple glycolipids. Samples of only 100-300 mug are required.