LIPID SEPARATION FROM URTICA-DIOICA - EXISTENCE OF PLATELET-ACTIVATING-FACTOR

The common wild plant nettle, especially Urtica dioica, is one of the most potent plants in producing direct irritation to the skin (urticar ia). In this study, total lipids of Urtica dioica were separated into neutral and polar lipids, which were further fractionated by high-perf ormance liquid chromatography(HPLC). Triglycerides, sterol-esters, fat ty acids, fatty acid methyl esters, glyceryl ethers, sterols, tocopher ols, diglycerides, and galactosyldiglycerides were identified as the m ain neutral lipid classes by comparing their retention times on an HPL C column and their migration following spraying with specific reagents on thin-layer chromatography (TLC) with standards. Four main classes of phospholipids (i.e., phosphatidylinositol, phosphatidylethanolamine , phosphatidylcholine, and lysophosphatidylcholine) were also identifi ed. A phospholipid that induced platelet aggregation was identified as platelet-activating factor on the basis of biological, chemical, and spectral methods.