Reducing Power of Simple Polyphenols by Electron-Transfer Reactions Using a New Stable Radical of the PTM Series, Tris(2,3,5,6-tetrachloro-4-nitrophenyl)methyl Radical

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• 作者：Josep Lluí ; s Torres ; Anna Carreras ; Aurora Jim&eacute ; nez ; Enric Brillas ; Xavier Torrelles ; Jordi Rius ; Luis Juliá
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：May 11, 2007
• 年：2007
• 卷：72
• 期：10
• 页码：3750 - 3756
• 全文大小：171K
• 年卷期：v.72,no.10(May 11, 2007)
• ISSN：1520-6904

文摘

<TR>The synthesis and characterization of a new radical and its use for testing the antioxidant activity ofpolyphenols by electron transfer are reported. This new and stable species of magnetic nature, tris(2,3,5,6-tetrachloro-4-nitrophenyl)methyl (TNPTM) radical, has been characterized by electron paramagnetic resonance and its molecular structure determined by X-ray analysis. This new radical of thePTM (perchlorotriphenylmethyl) series, unlike 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, is stablein conditions of hydrogen abstraction reactions. TNPTM radical is able to discriminate between theantioxidant activities of catechol and pyrogallol in hydroxylated solvent mixtures such as chloroform/methanol (2:1). These features determine the antioxidant/pro-oxidant character and the biological activitiesof natural and synthetic flavonoids.