Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d'Eccellenza MIUR, Università della Calabria, I-87030 Arcavacata di Rende (CS), Italy.
Phys Chem Chem Phys. 2010 Jul 21;12(27):7662-70. doi: 10.1039/b924521a. Epub 2010 Mar 29.
The effectiveness of naturally occurring antioxidant quercetin in the inactivation of the damaging lipid peroxide radical was investigated by means of hybrid density functional based approach, using the direct dynamics method, where the thermal rate constants were calculated using variational transition-state theory with multidimensional tunneling. H-atom abstraction in quercetin by CH(3)OO peroxide occurs preferentially at the 4'OH phenolic site, from both kinetic and thermodynamic points of view. In principle, the narrowness of the obtained adiabatic potential-energy profile makes the occurrence of a significant tunnelling contribution possible. In fact, this contribution enhances the value of the computed rate constant at 300 K from 1.94 x 10(1) to 9.63 x 10(3) M(-1) s(-1) indicating that quercetin is a potent natural antioxidant in trapping and scavenging free radicals.
通过混合密度泛函理论，采用直接动力学方法，利用变分过渡态理论和多维隧道效应，研究了天然抗氧化剂槲皮素在失活有害脂质过氧自由基方面的有效性。从动力学和热力学的角度来看，CH(3)OO 过氧化物在槲皮素中的 H 原子优先在 4'OH 酚部位被提取。原则上，获得的绝热势能曲线的狭窄性使得显著的隧道贡献成为可能。事实上，这种贡献将计算得到的 300 K 时的速率常数从 1.94 x 10(1)提高到 9.63 x 10(3) M(-1) s(-1)，表明槲皮素是一种有效的天然抗氧化剂，可以捕获和清除自由基。
