Evidence for alpha-tocopherol regeneration reaction of green tea polyphenols in SDS micelles.
Free Radic Biol Med
; 38(1): 78-84, 2005 Jan 01.
Article
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| MEDLINE
| ID: mdl-15589374
ABSTRACT
The synergistic antioxidant mechanism of alpha-tocopherol (vitamin E) with green tea polyphenols, i.e., (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), and gallic acid (GA), was studied by assaying the kinetics of the reaction of alpha-tocopheroxyl radical with green tea polyphenols by stopped-flow electron paramagnetic resonance, the inhibition of linoleic acid peroxidation by these antioxidants, and the decay of alpha-tocopherol during the peroxidation. It was found that the green tea polyphenols could reduce alpha-tocopheroxyl radical to regenerate alpha-tocopherol with rate constants of 0.45, 1.11, 1.31, 1.91, and 0.43 x 10(2) M(-1) s(-1) for EC, EGC, ECG, EGCG, and GA, respectively, in sodium dodecyl sulfate micelles. In addition, these second-order rate constants exhibited a good linear correlation with their oxidation potentials, suggesting that electron transfer might play a role in the reaction.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fenoles
/
Dodecil Sulfato de Sodio
/
Té
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Flavonoides
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Ácido Linoleico
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Alfa-Tocoferol
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Antioxidantes
Idioma:
En
Revista:
Free Radic Biol Med
Asunto de la revista:
BIOQUIMICA
/
MEDICINA
Año:
2005
Tipo del documento:
Article