QSARS for Acute Toxicity of Halogenated Benzenes to Bacteria in Natural Waters  

作　　者：GUANG-HUA LU CHAO WANG YU-MEI LI 

机构地区：[1]Key Laboratory for Integrated Regulation and Resources Exploitation on Shallow Lakes, Ministry of Education, College of Environmental Science and Engineering, Hohai University, Nanjing 210098, Jiangsu, China [2]School of Energy and Environmental Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China

出　　处：《Biomedical and Environmental Sciences》2006年第6期457-460,共4页生物医学与环境科学（英文版）

基　　金：This work was supported by the National 973 Great Foundation Research Item of China (2002CB412303) and the National Natural Science Foundation of Jiangsu Province (BK2004118).

摘　　要：Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth （24h-IC50） were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The logl/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters： logl/IC50 =-0.531（ELUMO）＋1.693（Qc）＋0.163（logP）＋3.375. This equation was found to fit well （r^2=0.860, s=0.106）, and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth （24h-IC50） were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The logl/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters： logl/IC50 =-0.531（ELUMO）＋1.693（Qc）＋0.163（logP）＋3.375. This equation was found to fit well （r^2=0.860, s=0.106）, and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.

关 键 词：River bacteria Acute toxicity QSARS Prediction model 

分 类 号：X131.2[环境科学与工程—环境科学]