Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Col. Vicentina, Iztapalapa, México DF, México.
J Phys Chem B. 2011 Nov 10;115(44):13101-9. doi: 10.1021/jp208315k. Epub 2011 Oct 18.
Reactions of sesamol with different free radicals, in lipid and aqueous media, have been studied at the M05-2X/6-311+G(d,p) level of theory in conjunction with the SMD continuum model. Different mechanisms of reaction have been considered as well as polar and nonpolar environments. According to the overall rate coefficients, sesamol is predicted to react significantly faster in aqueous solution than in nonpolar media. The polarity of the environment also changes the relative importance of the reaction mechanisms. The anionic form of sesamol was found to be particularly reactive toward peroxyl radicals by transferring one electron. This mechanism was found responsible for the exceptional peroxyl radical scavenging activity of sesamol in aqueous solution, which was found to be even better than carotenoids, 2-propenesulfenic acid, and glutathione under physiological conditions. The agreement between experimental and calculated data supports the presented results as well as the methodology used in this work.
在 M05-2X/6-311+G(d,p)理论水平上结合 SMD 连续模型研究了芝麻酚与不同自由基在脂相和水相中的反应。本文考虑了不同的反应机制以及极性和非极性环境。根据总的反应速率常数，预测芝麻酚在水溶液中的反应速度明显快于非极性介质。环境的极性也改变了反应机制的相对重要性。发现芝麻酚的阴离子形式通过转移一个电子对过氧自由基具有特别高的反应活性。这种机制负责芝麻酚在水溶液中具有异常高的过氧自由基清除活性，其活性甚至优于类胡萝卜素、2-丙烯亚磺酸和谷胱甘肽在生理条件下的活性。实验数据与计算数据之间的一致性支持了所提出的结果以及本文所用的方法。
