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应用密度泛函方法(DFT)在B3LYP/6-311G~(**)水平上全优化计算38个取代芳烃的量子化学参数,结合辛醇/水分配系数研究取代芳烃化合物对发光菌毒性的定量构效关系(QSAR)。对训练集样本经逐步多元回归分析(SMR)后,所建QSAR方程的复关系数R~2及去一法交互检验复相关系数Q_(LOO)~2分别为0.920和0.896,用预测集样本预测外部,所得外部预测样本复相关系数R_(ext)~2和外部预测集交互检验Q_(ext)~2分别为0.870和0.849。模型结果显示:辛醇/水分配系数愈大,即分子疏水性愈强,化合物对发光菌的毒性愈大;取代基的吸电子能力愈强,化合物毒性愈大;前沿轨道能级差愈小,化合物毒性愈大。
Quantum chemical parameters of 38 substituted aromatics were calculated by density functional theory (DFT) at B3LYP / 6-311G ~ (**) level. The octanol / water partition coefficient was used to study the quantification of the toxicity of substituted aromatic compounds Structure-activity relationship (QSAR). After the SMR of the training set samples, the complex correlation coefficient R ~ 2 and the complex correlation coefficient Q_ (LOO) ~ 2 of QSAR equation were 0.920 and 0.896, respectively. Using the prediction set samples Externally, the exponential R_ (ext) ~ 2 of exogenous forecasting sample and the exponential externality (Q_ (ext) ~ 2) of external forecasting set are 0.870 and 0.849, respectively. The results showed that the greater the octanol / water partition coefficient was, the stronger the hydrophobicity of the molecule was and the more toxic the compound was to the luminescent bacteria. The stronger the electron-withdrawing ability of the substituent was, the more toxic the compound was. The more toxic compounds.