Isolation and composition of inositolphosphorylceramide-type sphingolipids of hyphal forms of Candida albicans.

Abstract

Hyphal forms of the human pathogen Candida albicans have been found to contain substantial quantities of phosphosphingolipids. These lipids were fractionated into three classes by normal-phase high-performance liquid chromatography. The first class contained equimolar amounts of phosphorus, inositol, phytosphingosines, and fatty acids; their composition and chromatographic behavior suggest that these compounds are inositolphosphorylceramides. The second class contained equimolar amounts of phosphorus, mannosylinositol, phytosphingosines, and fatty acids; their composition and chromatographic behavior indicate that these compounds are mannosylinositolphosphorylceramides. The third class of compounds contained phosphorus, mannosylinositol, inositol, phytosphingosines, and fatty acids in a molar ratio of 2:1:1:1:1; their composition and chromatographic behavior indicate that these compounds are mannosyldiinositolphosphorylceramides. Molecular species in each class differ in the composition of long chain bases and fatty acids; the most abundant long chain bases were C18 and C20 phytosphingosines, and the most abundant fatty acids were hydroxy and nonhydroxy C24-26. The array of sphingolipids in C. albicans is similar to that of Saccharomyces cerevisiae. Sphingolipids have been shown to be essential in S. cerevisiae, thus these lipids, which are not present in animals, offer a potentially unique target for antifungal chemotherapy against C. albicans.