Isolation and characterization of addition products of alpha-tocopherol with peroxyl radicals of dilinoleoylphosphatidylcholine in liposomes.
alpha-Tocopherol was reacted with peroxyl radicals of phosphatidylcholine at 37 degrees C in liposomes. The phospholipid-peroxyl radicals were generated by the reaction of 1,2-dilinoleoyl-3-sn-phosphatidylcholine with a free radical initiator, 2,2'-azobis(2,4-di-methylvaleronitrile), under air. One peak corresponding to the reaction products of alpha-tocopherol with phosphatidylcholine-peroxyl radicals was isolated by reversed-phase high-performance liquid chromatography. Its structure was identified as a mixture of 8a-(phosphatidylcholine-peroxy)-alpha-tocopherones: 1-[9-(8a-peroxy-alpha-tocopherone)-10,12-octadecadienoyl]-2- linoleoyl-3-sn-phosphatidylcholine,1-[13-(8a-peroxy-alpha-tocopherone )-9,11-octadecadienoyl]-2-linoleoyl-3-sn-phosphatidylcholine, 1-linoleoyl-2-[9-(8a, peroxy-alpha-tocopherone)-10,12-octadecadienoyl]-3-sn-pho sph atidylcholine and 1-linoleoyl-2-[13-(8a-peroxy-alpha-tocopherone)-9,11-octadecadi enoyl]-3-sn- phosphatidylcholine. The results indicate that each alpha-tocopherol can trap two peroxyl radicals during the peroxidation of unsaturated phospholipid in liposomes.
Yamauchi
R
R
Department of Food Science, Faculty of Agriculture, Gifu University, Japan.
Yagi
Y
Y
Kato
K
K
D002851:Chromatography, High Pressure Liquid; D005609:Free Radicals; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014810:Vitamin E / Q000737:chemistry*
D005609:Free Radicals; D008081:Liposomes; D010545:Peroxides; D010713:Phosphatidylcholines; D014810:Vitamin E; C049375:perhydroxyl radical; C002448:1,2-linoleoylphosphatidylcholine