Oxidation of alpha-tocopherol during the peroxidation of dilinoleoylphosphatidylcholine in liposomes.

Article abstract of DOI:10.1271/bbb.60.616

Liposomal suspensions of dilinoleoylphosphatidylcholine (DLPC) containing alpha-tocopherol (0.1 mol%, based on DLPC were oxidized at 37 degrees C. The oxidation was initiated by a lipid-soluble or water-soluble free radical initiator, or by the addition of CuSO4 and fructose. In all the oxidation systems, alpha-tocopherol suppressed the formation of DLPC hydroperoxides until all the alpha-tocopherol had been depleted. The oxidation products of alpha-tocopherol were 8a-alkyldioxy-alpha-tocopherones, 5,6-epoxy-alpha-tocopherylquinone, 2,3-epoxy-alpha-tocopherylquinone, and alpha-tocopherylquinone. The 8a-alkyldioxy-alpha-tocopherones were decomposed in the liposomes primarily by being hydrolyzed to produce alpha-tocopherylquinone. The results indicate that alpha-tocopherol can trap peroxyl radical to form 8a-alkyldioxy-alpha-tocopherones which are hydrolyzed to alpha-tocopherylquinone in phospholipid bilayers. In another oxidation pathway, alpha-tocopherol may be oxidized by peroxyl radicals to form isomeric epoxy-alpha-tocopherylquinones.

Full text of DOI:10.1271/bbb.60.616

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Bioscience, Biotechnology, and Biochemistry
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Oxidation of α-Tocopherol during the Peroxidation of
Dilinoleoylphosphatidylcholine in Liposomes
Ryo Yamauchia, Yuko Yagia & Koji Katoa
a Department of Food Science, Faculty of Agriculture, Gifu University, 1–1 Yanagulo,
Gifu-shi Gifu 501–11, Japan
Published online: 12 Jun 2014.
To cite this article: Ryo Yamauchi, Yuko Yagi & Koji Kato (1996) Oxidation of α-Tocopherol during the Peroxidation of
Dilinoleoylphosphatidylcholine in Liposomes, Bioscience, Biotechnology, and Biochemistry, 60:4, 616-620, DOI: 10.1271/
bbb.60.616
To link to this article: http://dx.doi.org/10.1271/bbb.60.616
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