Novel gangliosides containing the sialyl-Le(a) structure from a human rectal adenocarcinoma

Oligosaccharides were released from the gangliosides of a human rectal adenocarcinoma with endoglycoceramidase (Rhodococcus sp. G-74-2) and then purified by affinity chromatography on a column of an immobilized monoclonal antibody, MSW 113. Structural studies, involving 600-MHz 1H NMR spectrometry, indicated the structures of these compounds to be as follows. [formula: see text] Three of these oligosaccharides, 2, 3, and 4, are novel as to ganglioside sugar chains and contain both lacto series types 1 and 2 chains. Oligosaccharides 3 and 4 are unique in that they contain the sialyl-Le(a)-X structure in linear and branched structures. Gangliosides with the oligosaccharide structures presented above might be new potential tumor markers.