QSAR Modeling of Toxicity of Quaternary Ammonium Compounds to Chiorella pyrenoidosa Using 2D and 3D Descriptors

To investigate the relationships between structures and toxicities of 13 quaternary ammonium compounds (QACs) to Chlorella pyrenoidosa, 2Dand 3D-QSAR models were built. The 2D-QSAR model included two parameters: averaged polarizability (α) and total connectivity (Tcon). Furthermore, 3D-QSAR models were proposed by using comparative molecular field analysis (CoMFA) and molecular similarity index analysis (CoMSIA). All these models were robust and predictive. To our interest, 3D-QSAR model suggested that the hydrophobicity of substituents was the dominating factor for the toxicities, electrostatic effect was the secondly important, and steric field gave the least contribution. Comparatively, the predictive ability of 3D-QSAR model is slightly more advantageous than that of 2D-QSAR. They can be used complementally in the toxicity description of this kind of compounds.