中文摘要：

目的采用密度泛函量子化学计算方法，在B3LYP／6-311＋＋G-水平上理论研究两种异黄酮抗氧化剂染料木素、大豆素的抗氧化活性能力。方法从平衡几何构型、前线分子轨道能隙及自由基生成热等角度分析影响异黄酮化合物抗氧化活性的因素，在分子层面上探讨异黄酮化合物的抗氧化作用机理。结果与结论抗氧化活性与清除活性氧的能力有关，电子越易转移，脱氢反应越易发生，则抗氧化活性越强，预测的抗氧化活性与实验结果一致。

英文摘要：

Objective To investigate the antioxidant activity of two isoflavones such as genistein and daidzein by using density functional level of theory at B3LYP/6-311＋＋G＊＊ basis set. Methods The geometry structures, frontier molecular orbital energy gap and enthalpy of radical formation were analyzed to explore the influential factors for antioxidant activity of two isoflavones. The main mechanism of antioxidant action was explored at the molecular level. Results and Conclusion The potentiality of antioxidant activity was highly related to active oxygen free radical scavenging capability. Because the easier the electron transfer and the hydrogen abstraction reaction was, the stronger the antioxidant ability would be. The calculated results were in good agreement with the antioxidant order reported by experimental results.