QSAR study on the toxicity of substituted benzenes to the algae ( Scenedesmus obliquus)

• Published in: Chemosphere (Oxford) 2001-07, Vol.44 (3), p.437-440
• Main Authors: Lu, Guang-Hua, Yuan, Xing, Zhao, Yuan-Hui
• Format: Article
• Language: English
• Subjects: 48h-EC 50; Animal, plant and microbial ecology; Applied ecology; Benzene Derivatives - toxicity; Biological and medical sciences; Chlorophyta - physiology; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Electrons; ELUMO; Fundamental and applied biological sciences. Psychology; Lethal Dose 50; Quantum chemical; Scenedesmus obliquus; Structure-Activity Relationship; Substituted benzenes; Water Pollutants, Chemical - toxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/S0045-6535(00)00214-9

50% effective inhibition concentration 48h-EC 50 of 40 substituted benzenes to the algae ( Scenedesmus obliquus) was determined. The energy of the lowest unoccupied molecular orbital ( E LUMO) was calculated by the quantum chemical method MOPAC6.0-AM1. By using E LUMO and the hydrophobicity parameter log K OW the quantitative structure–activity relationship model (QSAR) was developed: log 1/ EC 50 =0.272 log K OW − 0.659 E LUMO + 2.54, R 2=0.793, S.E.=0.316, F=71.07, n=40. A series of equations were obtained about the measured EC 50 values of different subclasses of compounds. For those compounds containing double –NO 2, their toxicity may be related chiefly to the intracellular reduction of –NO 2 obtaining electron, while for anilines and phenols, K OW contributes most to the QSAR and E LUMO very little.