Isolation and partial characterization of a major inositol-containing lipid in baker's yeast, mannosyl-diinositol, diphosphoryl-ceramide.

A polar lipid containing about 20 per cent of the lipid soluble inositol has been purified from cells of Saccharomyces cerevisiae. This compound labeled with (3)H-inositol, (32)P(i), or (14)C glucose was isolated from aqueous pyridine extracts by means of paper chromatography. Unlabeled compound was obtained by a differential solubility scheme. Analytical and degradation studies suggest that this compound can be formulated as a mannosyl-diinositol, diphosphoryl-ceramide. It can be converted by treatment with base or acid into a mannosylmonoinositol phosphoryl-ceramide, a composition which relates it to the basic structure of the phytoglycolipids.