alpha-L-Fucopyranosylceramide, a novel glycolipid accumulated in some of the human colon tumors.

A fucosylceramide was isolated from a ceramide monohexoside fraction of human colon carcinomas by acetylation followed by preparative thin layer chromatography on Silica Gel G developed with butylacetate. It contained only fucose as the carbohydrate component and the ceramide moiety was characterized as N-palmitoyloctadecasphingenine as a predominant component. The structure of the compound was determined as alpha-L-fucopyranosylceramide by methylation analysis, mass spectrometry of permethylated and reduced glycolipid, and by enzymatic hydrolysis with alpha-L-fucosidase. The chemical concentration of this compound in colon tumor tissue depends on degree of malignancy: highly malignant metastatic deposits from colon cancers were 3 to 70 ng/mg of residue protein, whereas that of localized colon tumor was 0 to 2 ng/mg of protein residue. The present observation offers additional support for the occurrence of metabolic abnormality of fucolipids as membrane phenotype of malignancy as was suggested in previous studies (Yang, H-J., and Hakomori, S. (1971) J. Biol. Chem. 246, 1192-1200; Steiner, S., Brennan, P.J., Melnick, J. L. (1973) Nature New Biol. 245, 19-21).