Effects of pH and Metal Ions on Antioxidative Activities of Catechins
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概要
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The Effects of pH on antioxidative activities of catechol, pyrogallol, and four catechins, and effects of metal ions (Al^<3+>, Ca^<2+>, Cd^<2+>, Co^<2+>, Cr^<3+>, Cu^<2+>, Fe^<2+>, Fe^<3+>, K^+, Mg^<2+>, Mn^<2+>, Na^+, and Zn^<2+>) on antioxidative activities of (-)-epigallocatechin gallate (EGCG) were studied by an oxygen electrode method. The antioxidative activities of catechins were high and constant at pH 6-12,but decreased in acidic and strong alkaline solutions. Copper (II) ion the most strongly increased the antioxidative activity of EGCG among these metal ions examined, but iron (II) ion largely inhibited the antioxidative activity of EGCG. These effects are discussed considering the formation of metal complexes with catechins and the change in oxidation potentials.
- 2001-01-23
著者
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Tabata M
Department Of Chemistry Faculty Of Science And Engineering Saga University
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Tabata Masaaki
Department Of Chemistry Faculty Of Science And Engineering Saga University
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Kumamoto Midori
Department Of Food And Nutrition Faculty Of Home Science Nishikyushu University
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Sonda T
Nishikyushu Univ. Saga Jpn
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Sonda Tamiyoshi
Department Of Health And Nutrition Science Faculty Of Health And Social Welfare Science Nishikyushu
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NAGAYAMA Kinuyo
Department of Food and Nutrition, Faculty of Home Science, Nishikyushu University
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Nagayama Kinuyo
Department Of Food And Nutrition Faculty Of Home Science Nishikyushu University
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Sonda Tamiyoshi
Department of Food and Nutrition, Faculty of Domestic Science, Nishikyushu University
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