IDENTIFICATION OF MOLECULAR-SPECIES OF PHOSPHOLIPIDS FROM PIG-HEART BY COMBINING CHROMATOGRAPHIC TECHNIQUES

Glycerophospholipids from subcellular organelles and membranes from pi g heart were divided into subclasses. The molecular species within the main subclasses were analyzed. The phosphorus moiety had been removed by phospholipase-C and the acetylated molecules were separated in dia cyl-, alkylacyl- and alkenylacyl-glycerols by thin-layer chromatograph y (TLC). For further identification the subclasses from the first frac tionation by TLC were separated by silver ion chromatography according to their polarity. A small portion of the acetylated diradyl-species was transesterified so that the fatty acid composition could be assess ed as methyl esters. The acetylated molecular species derived from gly cerophospholipids were chromatographed on WCOT fused silica columns wi th TAP as stationary phase according to molecular weight and unsaturat ion. Gaschromatography (GC) of fatty acid methyl esters and dimethylac etals from plasmalogens was executed on DEGS-columns or on WCOT fused silica columns with CP-Sil 88 as stationary phase. The distribution of molecular species within a phospholipid class (PC or PE) was rather s imilar for the diacyl- and the alkenylacyl molecules. But the latter a re more volatile. In the case of phosphatidylcholine the composition o f C-16-C-18-:1; C-16-C-18:2 and C-18-C-18:2 was predominant for diacyl - as well as alkenylacyl-species. In the case of phosphatidylethanolam ine the fatty acid composition of C-18-C-20:4 and C-18-C-18:2 were the most important species. The composition of fatty acids in diacyl- and alkenylacyl-species is of special interest as the metabolism of diacy l-glycerophospholipids is quite different from alkenylacyl-glycerophos pholipids.