Torres Josep Lluís, Carreras Anna, Jiménez Aurora, Brillas Enric, Torrelles Xavier, Rius Jordi, Juliá Luis
Institut d'Investigacions Químiques i Ambientals-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
J Org Chem. 2007 May 11;72(10):3750-6. doi: 10.1021/jo062665a. Epub 2007 Apr 17.
The synthesis and characterization of a new radical and its use for testing the antioxidant activity of polyphenols 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 the PTM (perchlorotriphenylmethyl) series, unlike 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, is stable in conditions of hydrogen abstraction reactions. TNPTM radical is able to discriminate between the antioxidant 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 activities of natural and synthetic flavonoids.
报道了一种新自由基的合成、表征及其通过电子转移用于测试多酚抗氧化活性的应用。这种具有磁性的新型稳定物种，即三（2,3,5,6 - 四氯 - 4 - 硝基苯基）甲基（TNPTM）自由基，已通过电子顺磁共振进行了表征，并通过X射线分析确定了其分子结构。与2,2 - 二苯基 - 1 - 苦基肼基（DPPH）自由基不同，PTM（全氯三苯甲基）系列的这种新自由基在氢提取反应条件下是稳定的。TNPTM自由基能够区分在诸如氯仿/甲醇（2:1）等羟基化溶剂混合物中儿茶酚和邻苯三酚的抗氧化活性。这些特性决定了天然和合成黄酮类化合物的抗氧化/促氧化特性及生物活性。
