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Electrochemical Behaviors of Quercetin and Kaempferol in Neutral Buffer Solution

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中国实验方剂学杂志 2002年第S1期8卷 -页

作者： kensuke Arai fumiyo kusu School of Pharmacy Tokyo University of Pharmacy and Life Science 14321Horinouchi Hachioji Tokyo1 Japan

Ｑｕｅｒｃｅｔｉｎａｎｄｋａｅｍｐｆｅｒｏｌ,ｆｌａｖｏｎｏｌｓ,ａｒｅｐｒｅｄｏｍｉｎａｎｔｉｎｖｅｇｅｔａｂｌｅｓａｎｄｆｒｕｉｔｓ ,ａｎｄａｒｅｃｏｍｐｏｎｅｎｔｓｉｎｔｈｅｈｕｍａｎｄｉｅｔ .[1] Ｔｈｅｙａｒ...

Ｑｕｅｒｃｅｔｉｎａｎｄｋａｅｍｐｆｅｒｏｌ,ｆｌａｖｏｎｏｌｓ,ａｒｅｐｒｅｄｏｍｉｎａｎｔｉｎｖｅｇｅｔａｂｌｅｓａｎｄｆｒｕｉｔｓ ,ａｎｄａｒｅｃｏｍｐｏｎｅｎｔｓｉｎｔｈｅｈｕｍａｎｄｉｅｔ .[1] Ｔｈｅｙａｒｅｒｅｐｏｒｔｅｄｔｏｂｅｐｏｔｅｎｔａｎｔｉｏｘｉｄａｎｔｓ .[2 ,3] Ｏｎｅｍｅｃｈａｎｉｓｍｏｆｔｈｅｉｒａｎｔｉｏｘｉｄａｎｔａｃｔｉｖｉｔｙｉｓｒｅｇａｒｄｅｄａｓｓｃａｖｅｎｇｉｎｇｆｒｅｅｒａｄｉｃａｌｓｂｙｄｏｎａｔｉｏｎｏｆｅｌｅｃｔｒｏｎｓ.[4]Ｓｏｋｎｏｗｌｅｄｇｅａｂｏｕｔｔｈｅｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｓｅｔｗｏｆｌａｖｏｎｏｌｓｃａｎｈｅｌｐｕｓｔｏｕｎｄｅｒｓｔａｎｄｔｈｅｉｒａｎｔｉｏｘｉｄａｎｔａｃｔｉｖｉｔｙ .Ｗｈｅｎｓｔｕｄｙｉｎｇｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｂｅｈａｖｉｏｒｏｆｆｌａｖｏｎｏｉｄｓｉｎｔｈｅｎｅｕｔｒａｌｂｕｆｆｅｒｓｏｌｕｔｉｏｎ ,[5 ] ｗｅｆｏｕｎｄｔｈａｔｑｕｅｒｃｅｔｉｎａｎｄｋａｅｍｐｆｅｒｏｌｇａｖｅａｒｅｖｅｒｓｉｂｌｅａｎｄａｎｉｒｒｅｖｅｒｓｉｂｌｅｃｙｃｌｉｃ...

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Relationship of Electrochemical Oxidation of Catechins on Their Antioxidant Activity in Microsomal Lipid Peroxidation

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中国实验方剂学杂志 2002年第S1期8卷 -页

作者： Akira Kotani kensuke Arai fumiyo kusu

Ｃａｔｅｃｈｉｎｓ (Ｆｉｇ .1 ) ,ｔｈｅｍａｉｎｃｏｎｓｔｉｔｕｅｎｔｓｉｎｇｒｅｅｎｔｅａ ,ｈａｖｅａｔｔｒａｃｔｅｄｌａｓｔｉｎｇｉｎｔｅｒｅｓｔｂｅｃａｕｓｅｏｆｔｈｅｉｒｗｉｄｅｂｉｏｌｏｇｉｃａｌｅｆｆｅｃ...

Ｃａｔｅｃｈｉｎｓ (Ｆｉｇ .1 ) ,ｔｈｅｍａｉｎｃｏｎｓｔｉｔｕｅｎｔｓｉｎｇｒｅｅｎｔｅａ ,ｈａｖｅａｔｔｒａｃｔｅｄｌａｓｔｉｎｇｉｎｔｅｒｅｓｔｂｅｃａｕｓｅｏｆｔｈｅｉｒｗｉｄｅｂｉｏｌｏｇｉｃａｌｅｆｆｅｃｔｓ.Ｒｅｃｅｎｔｌｙ ,ｔｈｅａｎｔｉｏｘｉｄａｎｔａｃｔｉｖｉｔｙ (ＡＡ)ｏｆｃａｔｅｃｈｉｎｓｈａｓｂｅｅｎｗｉｄｅｌｙｒｅｐｏｒｔｅｄ .Ｃａｔｅｃｈｉｎｓｅｆｆｅｃｔｉｖｅｌｙｓｕｐｐｒｅｓｓｅｄｌｉｐｉｄｐｅｒｏｘｉｄａｔｉｏｎ (ＬＰＯ)ｉｎｂｉｏｌｏｇｉｃａｌｔｉｓｓｕｅｓａｎｄｓｕｂｃｅｌｌｕｌａｒｆｒａｃｔｉｏｎｓｓｕｃｈａｓｍｉｔｏｃｈｏｎｄｒｉａ ,ｍｉｃｒｏｓｏｍｅｓ ,ｌｉｐｏｓｏｍｅｓ ,ａｎｄｌｏｗｄｅｎｓｉｔｙｌｉｐｏｐｒｏｔｅｉｎｓ(ＬＤＬ) .[1～ 5 ] Ｏｎｔｈｅｏｔｈｅｒｈａｎｄ ,ｔｈｅｙｅｘｈｉｂｉｔｅｄｓｃａｖｅｎｇｉｎｇａｃｔｉｖｉｔｙｏｎｆｒｅｅｒａｄｉｃａｌｓ ,ｓｕｃｈａｓ 1 ,1’ ｄｉｐｈｅｎｙｌ 2 ｐｉｃｒｙｌｈｙｄｒａｚｙｌ (ＤＰＰＨ )ｒａｄｉｃａｌ,ｓｕｐｅｒｏｘｉｄｅａｎｉｏｎ ,ｈｙｄｒｏｘｙｌｒａｄ...

关键词：

Estimation of the Antioxidant Activities of Flavonoids from Their Oxidation Potentials

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中国实验方剂学杂志 2002年第S1期8卷 -页

作者： kensuke ARAI fumiyo kusu Akira KOTANI School of Pharmacy Tokyo University of Pharmacy and Life Science Tokyo University of Pharmacy and Life Science 14321Horinouchi Hachioji Tokyo192-0392 Japan 14321Horinouc

Ａｓｉｍｐｌｅｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｍｅｔｈｏｄｆｏｒｅｓｔｉｍａｔｉｎｇｔｈｅａｎｔｉｏｘｉｄａｎｔａｃｔｉｖｉｔｙ (ＡＡ)ｏｆｆｌａｖｏｎｏｉｄｓｈａｓｂｅｅｎｄｅｖｅｌｏｐｅｄ .Ｔｈｅｐｒｏｐｏｓｅｄｍ...

Ａｓｉｍｐｌｅｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｍｅｔｈｏｄｆｏｒｅｓｔｉｍａｔｉｎｇｔｈｅａｎｔｉｏｘｉｄａｎｔａｃｔｉｖｉｔｙ (ＡＡ)ｏｆｆｌａｖｏｎｏｉｄｓｈａｓｂｅｅｎｄｅｖｅｌｏｐｅｄ .Ｔｈｅｐｒｏｐｏｓｅｄｍｅｔｈｏｄｉｓｂａｓｅｄｏｎａｍｅａｓｕｒｅｍｅｎｔｏｆｔｈｅｈａｌｆｗａｖｅｐｏｔｅｎｔｉａｌ(Ｅ1/2 )ｏｆｔｈｅｆｉｒｓｔｏｘｉｄａｔｉｏｎｗａｖｅｏｆｆｌａｖｏｎｏｉｄｓｂｙｕｓｉｎｇｆｌｏｗｔｈｒｏｕｇｈｃｏｌｕｍｎｅｌｅｃｔｒｏｌｙｓｉｓ.Ａｔｔｈｅｓａｍｅｔｉｍｅ ,ｔｈｅｌｉｐｉｄｐｅｒｏｘｉｄａｔｉｏｎ (ＬＰＯ)ｉｎｈｉｂｉｔｉｎｇｅｆｆｅｃｔｓｏｆｔｈｅｓｅｆｌａｖｏｎｏｉｄｓｗｅｒｅｄｅｔｅｒｍｉｎｅｄ .ＡｑｕａｎｔｉｔａｔｉｖｅｓｔｒｕｃｔｕｒｅａｃｔｉｖｉｔｙｒｅｌａｔｉｏｎｓｈｉｐｗａｓｏｂｔａｉｎｅｄｔｏｄｅｓｃｒｉｂｅｔｈｅＡＡｏｆｆｌａｖｏｎｏｉｄｓ:ＩＣ5 0 (μＭ ) =3 0 .3 6+1 51 .50Ｅ1/2 (Ｖ) - 1 2 .63ｌｏｇＰ(ｒ =0 .852 ) ,ｗｈｅｒｅＩＣ5 0 ｒｅｐｒｅｓｅｎｔｓｔｈｅｃｏｎｃｅｎｔ...

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槲皮素和山奈酚在中性缓冲液中的电化学行为(英文)

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槲皮素和山奈酚在中性缓冲液中的电化学行为(英文)

作者：杨滨 kensuke Arai fumiyo kusu School of Pharmacy Tokyo University of Pharmacy and Life Science 1432-1 HorinouchiHachiojiTokyo 192-0392Japan

Quercetin and kaempferol,flavonols,are predominant in vegetables and fruits,and are components in the human *** are reported to be potent *** mechanism of their antioxidant activity is regarded as scavenging free radicals by donation of electrons. So knowledge about the electrochemical properties of these two flavonols can help us to under-

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流动柱电极电解法测定黄酮化合物的氧化电位(英文)

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流动柱电极电解法测定黄酮化合物的氧化电位(英文)

作者：杨滨 kensuke Arai fumiyo kusu School of Pharmacy Tokyo University of Pharmacy and Life Science 1432-1 HorinouchiHachiojiTokyo 192-0392Japan

The first oxidation potentials of a series of structurally related flavonoids,mostly having hydroxyl substituents, were investigated by employing cyclic voltammetry and flow-through column *** flow-through column packed with carbon fibers was useful for determining the half-wave potenital(E) of the flavonoids and the number of electrons(n-value) transferred in the oxidation *** potentials of the flavonoids were shown to be strongly dependent on their *** important determinants for the ease of oxidation are:1) ortho-trihydroxyl group(pyrogallol group);2) ortho-dihydroxyl group(catechol group);3) the presence of a 2,3-double bond in conjugation with 4-oxo and 3-hydroxyl groups;and 4)another addition of a resonance-effective *** relaton between the E values of the first oxidation step obtained from the hydrodynamic voltammograms and the antioxidant data(IC) in biological systems obtained from references was examined to determine whether the E value was an indicator of the biological *** was found that more negative E values of flavonoids were usually associated with decreasing IC *** findings suggest that the electrochemical properties of the flavonoids contribute to their antioxidant activity,and thus the E values of flavonoids can be used as indices of their antioxidant activities in biological systems.

关键词： Flavonoids First Oxidation Potential Column Electrode Antioxidant Activity

E 以氧化电位评价黄酮化合物的抗氧化作用(英文)

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E 以氧化电位评价黄酮化合物的抗氧化作用(英文)

作者：杨滨 Akira KOTANI kensuke ARAI fumiyo kusu School of Pharmacy Tokyo University of Pharmacy and Life Science 1432-1 HorinouchiHachiojiTokyo 192-0392Japan

A simple electrochemical method for estimating the antioxidant activity(AA)of flavonoids has been *** proposed method is based on a measurement of the half-wave potential (E1/2)of the first oxidation wave of flavonoids by using flow-through column *** the same time,the lipid peroxidation(LPO)inhibiting effects of these flavonoids were determined. A quantitative structure-activity relationship was obtained to describe the AA of

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儿茶素电氧化与其在微粒体脂质过氧化中抗氧化作用的关系(英文)

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儿茶素电氧化与其在微粒体脂质过氧化中抗氧化作用的关系(英文)

作者：杨滨 Akira KOTANI kensuke ARAI fumiyo kusu School of Pharmacy Tokyo University of Pharmacy and Life Science 1432-1 HorinouchiHachiojiTokyo 192-0392Japan

The oxidation potentials of catechins were measured by employing flow-through column *** oxidation potentials of catechins were shown to depend on their *** the same time,the antioxidant activity of catechins on NADPH-dependent lipid peroxidation in rat liver microsomes was *** showed a 50%inhibition of lipid peroxidation in the concentration range of 10-51μ*** those studied,galloylated catechins exhibited stronger antioxidant activities than those of nongalloylated catechins.A quantitative relationship has been obtained to describe the antioxidant activity of catechins:log IC(μM)=1.56+2.49E(V)- 0.29log P(r=0.907),where IC represents the concentration for 50%inhibition of lipid peroxidation,E represents the half-wave potential of the first oxidation wave,and P represents the octanol/water partition coefficient. This relationship suggested two important characteristics determining catechin antioxidant activity,namely the ease of oxidation and the lipophilicity.

关键词： catechin oxidation potential microsomal lipid peroxidation lipophilicity