Phospholipid molecular species distribution of some medically important Candida species analysed by fast atom bombardment mass spectroscopy.

The aim of this study was to obtain detailed information on phospholipids (PL) of the medically important Candida species and to determine their possible chemotaxonomic significance. Lipids were extracted from 22 strains representing 8 Candida species and their PL molecular species distributions were determined by Fast Atom Bombardment Mass Spectroscopy (FAB MS) in negative ion mode. Fifteen major lower mass peaks (m/z 221 to 289) were attributable to the expected presence of carboxylate anions and 24 major higher mass peaks (m/z 557 to 837) were attributable to phospholipid anions. Major carboxylate peaks were of the following m/z and identities : 253, C16:1; 255, C16:0; 277, C18:3; 279, C18:2; 281, C18:1; and 283, C18:0. The most abundant peaks consistent with the presence of phospholipid molecular species anions include those of m/z 673, 743, 833, 834 and 836 tentatively identified as phosphatidic acid (PA) (34:1), phosphatidylglycerol (PG) (34:3), phosphtidylinositol (PI) (34:2) and two unknown molecular species. This profile is diagnostic for the genus Candida. Quantitative differences were observed between different Candida species. Thus, polar lipid molecular species distribution in Candida spp. has chemotaxonomic significance, especially so in the case of carboxylate anions.