Oxidative degradation of glycosphingolipids revisited: a simple preparation of oligosaccharides from glycosphingolipids

In order to cleave gangliosides and isolate the oligosaccharide portion, the allylic nature of OH-3 of the sphigenine base was utilized in its selective oxidation to a ketone group by 2,3-dichloro-5,6-dicyanobenzoquinone. Triethylamine treatment of the oxidation products resulted in the β-elimination of the intact oligosaccharide. The isolation of the pure oligosaccharide from the modified ceramide residue and unreacted ganglioside was obtained by liquid chromatography. Preliminary investigations suggest that the same reaction conditions can be used for an analogous elimination of oligosaccharides linked to the serine or threonine residues of glycoproteins.