Gangliosides of bovine buttermilk. Isolation and characterization of a novel monosialoganglioside with a new branching structure.

Bovine buttermilk was found to contain 0.92 mumol of lipid-bound sialic acid/g dry weight. On ganglioside mapping, at least seven gangliosides were detected, and the structures of the five major molecules were determined by degradation with exoglycosidases and methylation analysis. GM3, GD3, and GT3 were found to comprise 80% of the total gangliosides. The other two gangliosides had a new core structure with a branched oligosaccharide chain. One was a novel monosialoganglioside with a 2----6 linked sialic acid residue with the following structure: (Formula, see text) There were 41 nmol of this ganglioside/g of buttermilk (4.5% of total gangliosides). The other was a trisialogangliosides with the above new core structure.