Studies on glycosphingolipids of fresh-water bivalves. III. Isolation and characterization of a novel globoside containing mannose from spermatozoa of the fresh-water bivalve, Hyriopsis schlegelii.

Three globosides were isolated from spermatozoa of the fresh-water bivalve, Hyriopsis schlegelii by mild alkaline hydrolysis, acetone precipitation, Unisil column chromatography and preparative thin-layer chromatography. These globosides are unique in their sugar chains, since they contain mannose instead of galactose found so far in all globosides of mammals and other animals examined. The main globoside in the spermatozoa was characterized as Glc-NAcbeta(1 leads to 2)Manbeta(1 leads to 3)Manbeta(1 leads to 4)Glcbeta(1 leads to 1)-ceramide by partial acid hydrolysis, analysis of its anomeric configuration with chromium trioxide, methylation analysis and enzymatic hydrolysis. The globoside contained normal saturated fatty acids ranging in length from C16 to C21, palmitic and stearic acids being predominant. Its main long-chain was octadeca-4-sphingenine.