Queiroz Auriekson N, Gomes Bruno A Q, Moraes Waldir M, Borges Rosivaldo S
Laboratório de Química Farmacêutica, Faculdade de Farmácia, Instituto de Ciências da Saúde, Universidade Federal do Pará, Augusto Correa, SN, 66075-110 Belém, PA, Brazil.
Eur J Med Chem. 2009 Apr;44(4):1644-9. doi: 10.1016/j.ejmech.2008.09.023. Epub 2008 Sep 30.
The structure-activity relationship has been used to study the determination of antioxidant pharmacophore for resveratrol using quantum chemistry calculations by the Functional of Density Theory method. According to the geometry obtained by using a B3LYP/6-31G(*), the HOMO, ionization potential, bond dissociation energies, stabilization energies, and spin density distribution, the electron or hydrogen abstraction in para position is more favored than in meta positions for resveratrol and related derivatives because of the resonance effects. Comparison with structurally related compounds revealed that the antioxidant pharmacophore of resveratrol is 4-hydroxystilbene. Spin distribution showed that the pi-type electron system determines the stability of radicals and the unpaired electrons are mainly distributed to the O-atom in para position, double bond, and B-benzene ring. The antioxidant activity of resveratrol is related to the stabilization energy of 4-hydroxystilbene in resveratrol hydroxylated derivatives. Furthermore, the results explain the activity difference between resveratrol and its hydroxylated derivatives.
利用密度泛函理论方法通过量子化学计算，结构-活性关系已被用于研究白藜芦醇抗氧化药效团的确定。根据使用B3LYP/6-31G(*)得到的几何结构、最高占据分子轨道（HOMO）、电离势、键解离能、稳定化能和自旋密度分布，由于共振效应，白藜芦醇及其相关衍生物在对位的电子或氢提取比间位更有利。与结构相关化合物的比较表明，白藜芦醇的抗氧化药效团是4-羟基茋。自旋分布表明，π型电子体系决定了自由基的稳定性，未成对电子主要分布在对位的O原子、双键和B苯环上。白藜芦醇的抗氧化活性与白藜芦醇羟基化衍生物中4-羟基茋的稳定化能有关。此外，结果解释了白藜芦醇及其羟基化衍生物之间的活性差异。
