León-Carmona Jorge Rafael, Martínez Ana, Galano Annia
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México , Circuito Ext. s/n, Ciudad Universitaria, P.O. Box 70-360, Coyoacán, C.P. 04510, México.
J Phys Chem B. 2014 Aug 28;118(34):10092-100. doi: 10.1021/jp505586k. Epub 2014 Aug 14.
A new family of free radicals, that are soluble in water and stable at all pH values, were recently synthesized and used to assess the antiradical capacity of several polyphenols. In the present work, density functional calculations were used to investigate the single electron transfer reactions between these new free radicals and polyphenols in aqueous solution. The quantification of the antiradical capacity is a challenge, particularly for polyphenols, since they become unstable under experimental conditions. It was found that the electron transfer from polyphenols to the newly developed free radicals can be used to assess the efficiency of this kind of compound for preventing oxidative stress. Since one of the free radicals can be deprotonated under experimental conditions, this newly synthesized radical can help distinguish more clearly between different antiradical compounds with similar antioxidant capacity by modifying the pH in the experiments. The results reported here are in good agreement with the available experimental data and allowed making recommendations about possible experimental conditions in the design of antioxidant assays using the investigated radicals.
最近合成了一类新的自由基，它们可溶于水且在所有pH值下都稳定，并用于评估几种多酚的抗自由基能力。在本工作中，使用密度泛函计算来研究这些新自由基与水溶液中多酚之间的单电子转移反应。抗自由基能力的量化是一项挑战，特别是对于多酚而言，因为它们在实验条件下会变得不稳定。研究发现，多酚向新开发的自由基的电子转移可用于评估这类化合物预防氧化应激的效率。由于其中一种自由基在实验条件下可以去质子化，这种新合成的自由基可以通过在实验中改变pH值，更清楚地区分具有相似抗氧化能力的不同抗自由基化合物。此处报道的结果与现有实验数据高度吻合，并为使用所研究的自由基设计抗氧化测定的可能实验条件提供了建议。
