硝基芳烃对呆鲦鱼急毒性的DFT研究

DFT Study on Nitroaromatics' Acute Toxicities to Pimephales Promelas

对20种硝基芳烃化合物进行DFT-B3LYP/6-311G**水平全优化计算。据所得量子化学参数建立硝基芳烃对呆鲦鱼急毒性(-lg LC50)的QSAR模型,采用内部及外部双重验证的办法深入分析和检验模型的稳健性。最佳模型的复相关系数(R2)、去一法(LOO)交互检验复相关系数(R2cv)、外部预测样本复相关系数(R2ext)分别为0.927、0.915和0.877,故所建立QSAR模型的稳定性和预测能力良好。结果表明:硝基芳烃化合物的毒性主要由分子最低空轨道能(ELUMO)、分子总能量(ET)和氢原子所带的最高正电荷(QH+)决定。

To calculate the molecular geometries and electronic structures of 20 nitroaronlatics using the DFT-B3LYP method and with the basis set 6-311G＊＊. To select EHOMO,ELUMO,EXUOMO,EXLUMO,ET,qn,q,u and V as structural descriptors. To use the acute toxicity （-lg LC50）of these compounds to pimephales promelas along with the above nine structural parameters established the quantitative structure-aclivity relationships （QSAR）by muhiple linear regression. To analyze the estimation stability and generalization ahility of the model strictly by both internal and external validation. The correlation coefficient （Re ）, leave-one-out （LOO） cross validation Rev^2 , predictcd values versus experimental ones of external samples Rcxi, of established the best model are 0. 927,0. 913 and 0. 877. respectively. These show that the QSAR model has both favorable estimation stability and good prediction capal）ility. The results indicate that there is a good multivariate linear relationship between the experimental values of the acute toxicity to pimephales prometas and the energy of the lowest unoccupied molecular orbital, the rural energy of the molecular, the highest positive charge.