QSAR Modeling of Toxicity of Acyclic Quaternary Ammonium Compounds on Scenedesmus Quadricauda Using 2D and 3D Descriptors

Optimized calculation of typical acyclic quaternary ammonium compounds (QACs) was performed at B3LYP/6-311G** level using density functional theory (DFT) method. A two- dimensional quantitative structure–activity relationship (2D-QSAR) model was established with the obtained structure parameters as theoretical descriptors. And then three-dimensional quantitative structure–activity relationship (3D-QSAR) models were built using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods respectively. The 2D and 3D QSAR models exhibit optimum stability and predictive ability, revealing that steric and electronic effects influence the toxicity of acyclic QACs to Scenedesmus Quadricauda mostly.