Isolation and chemical composition of the ceramide of the Candida lipolytica yeast.

Candida lipolytica yeast was grown batchwise on glucose medium. Ceramide was quantitatively isolated from sphingolipid fractions of total lipids by a combination of column chromatography and preparative thin-layer chromatography. Fatty acids and long-chain bases, obtained after acid methanolysis, were analyzed by gas-liquid chromatography. Fatty acid composition was characterized by predominance of fatty acids shorter than 20 carbon atoms (72.2% of total fatty acids) and by high concentration of fatty acids with 16 carbon atoms (43.3% of total fatty acids). The dominant fatty acids were h16:0 and 18:1. The major fatty acid with more than 20 carbon atoms was h24:0. Hydroxylated fatty acids quantitatively represented almost half of the total fatty acids. The ceramide contained an unusual long-chain base composition. Besides the well-known trihydroxy bases, 18- and 20-phytosphingosine, which is a common characteristic for yeast sphingolipids, a high proportion of more polar bases than the trihydroxy ones, was found. The structures of 4,5-dihydroxyicosasphinanine (1,3,4,5-tetrahydroxy-2-aminooctadecane) and 4,5-dihydroxyicosasphinganine (1,3,4,5-tetrahydroxy-2-aminoeicosane) were tentatively assigned to these bases. Their chromatographic properties were identical to those of synthetic bases.