【摘要】 应用密度泛函方法(DFT)在B3LYP/6-311G**水平上全优化计算25个取代芳烃的量子化学参数,结合疏水性参数与化合物对呆鲦鱼的急性毒性进行定量构效关系研究(QSAR)。经逐步回归筛选变量后,所建多元线性回归方程的相关系数R及去一法交互检验复相关系数R2cv分别为0.967和0.907。用预测集样本进行了外部预测,所得外部预测样本复相关系数R2ext和外部预测集交互检验Q2ext分别为0.881和0.836。模型结果显示:分子疏水性参数logP较大时具有较大的脂溶性,化合物的毒性较大;取代基的吸电子能力越强,苯环的正电性越大,化合物的毒性越大。更多还原

【Abstract】 DFT-B3LYP method,with the basis set 6-311G,was employed to calculate the molecular geometric and electronic structures of 25 substituted aromatic hydrocarbons.The acute toxicities of these compounds to pimephales promelas along with the above descriptors and the octanol-water partition coefficient were used to establish the quantitative-activity relationships.The variables were reduced using stepwise multiple regression(SMR)method for the training set,and the statistical results indicated that the correlation coefficient in the multiple linear regression and cross validation using leave one out were 0.967 and 0.907 respectively.To validate the predictive power of resulting model,external validation were performed with R2ext and Q2ext values of 0.881 and 0.836 respectively.Results showed that the acute toxicities were increased with the increase of octanol-water partition coefficient.The substituted groups which have strong electron-accepting ability would enhance the toxicities.更多还原