Galano Annia, Francisco Marquez Misaela, Pérez-González Adriana
Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa , San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, C.P. 09340 México D. F., México.
Chem Res Toxicol. 2014 May 19;27(5):904-18. doi: 10.1021/tx500065y. Epub 2014 Apr 14.
Several aspects related to the antioxidant activity of ellagic acid were investigated using the density functional theory. It was found that this compound is unusually versatile for protecting against the toxic effects caused by oxidative stress. Ellagic acid, in aqueous solution at physiological pH, is able of deactivating a wide variety of free radicals, which is a desirable capability since in biological systems, these species are diverse. Under such conditions, the ellagic acid anion is proposed as the key species for its protective effects. It is predicted to be efficiently and continuously regenerated after scavenging two free radicals per cycle. This is an advantageous and unusual behavior that contributes to increase its antioxidant activity at low concentrations. In addition, the ellagic acid metabolites are also capable of efficiently scavenging a wide variety of free radicals. Accordingly, it is proposed that the ellagic acid efficiency for that purpose is not reduced after being metabolized. On the contrary, it provides continuous protection against oxidative stress through a free radical scavenging cascade. This is an uncommon and beneficial behavior, which makes ellagic acid particularly valuable to that purpose. After deprotonation, ellagic acid is also capable of chelating copper, in a concentration dependent way, decreasing the free radical production. In summary, ellagic acid is proposed to be an efficient multiple-function protector against oxidative stress.
利用密度泛函理论研究了与鞣花酸抗氧化活性相关的几个方面。研究发现，这种化合物在防止氧化应激引起的毒性作用方面具有异常的多功能性。在生理pH值的水溶液中，鞣花酸能够使多种自由基失活，这是一种理想的能力，因为在生物系统中，这些自由基种类繁多。在这种条件下，鞣花酸阴离子被认为是其发挥保护作用的关键物种。预计每循环清除两个自由基后，它能高效且持续地再生。这是一种有利且不寻常的行为，有助于在低浓度下提高其抗氧化活性。此外，鞣花酸代谢产物也能够高效清除多种自由基。因此，有人提出鞣花酸在此目的上的效率在代谢后不会降低。相反，它通过自由基清除级联反应提供对氧化应激的持续保护。这是一种罕见且有益的行为，使得鞣花酸在此方面特别有价值。去质子化后，鞣花酸还能够以浓度依赖的方式螯合铜，减少自由基的产生。总之，鞣花酸被认为是一种针对氧化应激的高效多功能保护剂。
