RADICAL EXCHANGE-REACTIONS BETWEEN VITAMIN-E, VITAMIN-C AND PHOSPHOLIPIDS IN AUTOXIDIZING POLYUNSATURATED LIPIDS

Antioxidant reactions of mixtures of vitamin E, vitamin C and phosphol ipids in autoxidizing lipids at 90 degrees C have been studied by ESR spectroscopy. When the phospholipid contained a tertiary amine (e.g. p hosphatidylcholine), the vitamin C and the vitamin E radicals were suc cessively observed as these two vitamins were sequentially oxidised du ring lipid oxidation. in the presence of the primary amine contained i n phosphatidylserine, the vitamin E oxidation was delayed for a few ho urs. in this case neither the vitamin C, nor the vitamin E radicals bu t a nitroxide radical derived from the phospholipid was observed. Simi lar results to those obtained with PS were obtained in the presence of either phosphatidylethanolamine or soybean lecithin. The participatio n in the radical reactions of phospholipids possessing a primary amine can therefore explain the synergistic effect of these phospholipids i n a mixture of vitamins E and C.