硝基芳烃对黑头呆鱼毒性的DFT研究  

DFT study on nitroaromatics toxicity to Fathead minnow

作　　者：彭艳芬[1] 刘天宝[1] 严永新[1] 汪新[1] 

机构地区：[1]池州学院化学材料与工程实验中心,安徽池州247000

出　　处：《计算机与应用化学》2013年第4期383-385,390,共4页Computers and Applied Chemistry

基　　金：国家自然科学基金资助项目(21101019;21271035);绿色高分子材料安徽省重点实验室开放课题基金资助项目(KF2012001)

摘　　要：对35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和标题化合物的辛醇/水分配系数(IgK_(OW))建立硝基芳烃对黑头呆鱼毒性(-IgLC_(50))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(R^2),去一法(LOO)交互检验复相关系数(R^2_(cv)),外部预测样本复相关系数(R^2_(ext))分别为0.975,0.970和0.904,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(E_(LUMO))、硝基静电荷(Q_(NO_2))、氢原子所带的最高正电荷(Q_H^+)及辛醇/水分配系数决定。苯环上取代基的类型、数目和取代位置直接影响到标题化合物的毒性大小,强吸电子基如硝基会使化合物毒性增强,且邻对位硝基取代的毒性高于间位取代;相反,给电子基团氨基的存在则会使化合物的毒性降低。总之,硝基是这类化合物致毒的主要基团,将硝基包覆或还原为氨基应为此类化合物解毒的重要途径。Study on quantitative structure-activity relationship （QSAR） of chloroaromatics would be helpful in researching for chloroaromatics activity. The DFT-B3LYP method, with the basis set 6-311G, was employed to calulate the molecular geometries and electronic structures of 22 chloroaromatics. EHoMo, ELtO, ENaoao, ENLtnaO, ET, Qa＋, Qso2, p and V were selected as structural descriptors. The acute toxicity （-lg LCs0） of these compounds to Guppy, and the above nine structural parameters, was used to established the QSAR model by multiple linear regression. The variables were reduced using stepwise multiple regression method, and the statistical results indicated that the correlation coefficient in the multiple linear regression and cross validation using leave-one-out were 0.963 and 0.962, respectively. To validate the predictive power of resulting model, external validation were performed with R2ext and Q2cxt values of 0.968 and 0.820, respectively. These showed that the QSAR model had good stability and predictability. The results indicate that there is a good multivariate linear relationship between the acute toxicity （-lg LCso） of chloroaromatics and the total energy of the molecular, molecular volume and energy of the next lowest unoccupied molecular orbital.

关 键 词：氯代芳烃 密度泛函理论 定量构效关系 戈卑鱼 

分 类 号：O641[理学—物理化学]