QSAR study on the toxicity of substituted benzenes to the algae (Scenedesmus obliquus).
50% effective inhibition concentration 48h-EC50 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: log1/EC50=0.272 logK(OW) - 0.659E(LUMO) + 2.54, R2 = 0.793, S.E. = 0.316, F = 71.07, n = 40. A series of equations were obtained about the measured EC50 values of different subclasses of compounds. For those compounds containing double -NO2, their toxicity may be related chiefly to the intracellular reduction of -NO2 obtaining electron, while for anilines and phenols, K(OW) contributes most to the QSAR and E(LUMO) very little.
Lu
G H
GH
Department of Environmental Science, Northeast Normal University, Changchun, People's Republic of China. leich@nenu.edu.cn
Yuan
X
X
Zhao
Y H
YH
D001555:Benzene Derivatives / Q000633:toxicity*; D000460:Chlorophyta / Q000502:physiology*; D004583:Electrons; D007928:Lethal Dose 50; D013329:Structure-Activity Relationship; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D001555:Benzene Derivatives; D014874:Water Pollutants, Chemical