Free-radical scavenging reaction of gamma-tocopherol during the decomposition of lipid hydroperoxides

Research Project

Project/Area Number	26450155
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Food science
Research Institution	Gifu University
Principal Investigator	Yamauchi Ryo 岐阜大学, 応用生物科学部, 教授 (50126760)
Project Period (FY)	2014-04-01 – 2017-03-31
Project Status	Completed (Fiscal Year 2016)
Budget Amount *help	¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000) Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2014: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Keywords	γ-トコフェロール / ビタミンＥ / 脂質過酸化 / 脂質ヒドロペルオキシド / フリーラジカル / ミセル / リポソーム / 脂質過酸化二次反応 / 抗酸化 / ミセル溶液 / 酸化二次反応
Outline of Final Research Achievements	γ-Tocopherol (γ-TH) was reacted with free radicals from the iron- or heme-catalyzed decomposition of lipid hydroperoxides. The iron-catalyzed reaction between γ-TH and methyl linoleate hydroperoxides (MeL-OOH) in toluene gave adducts of γ-TH with peroxyl radicals originated from MeL-OOH derived alkoxyl and peroxyl radicals in addition to tocored and γ-TH dimers. The formed γ-TH dimers also trapped the MeL-OOH derived peroxyl radicals. Next, the effect of γ-TH on the hemin- or myoglobin-catalyzed decomposition of 1-palmitoyl-2-linoleoyl-3-sn-phosphatidylcholine hydroperoxide (PLPC-OOH) in micelles and liposomes was studied. The reaction products were characterized to be adducts of γ-TH with PLPC-OOH derived peroxyl and alkyl radicals. γ-TH suppressed the formation of secondary aldehydic products during the decomposition of PLPC-OOH. The results indicated that γ-TH might suppress the formation of aldehydes by trapping the PLPC-OOH derived free radicals.