Modeling Ecotoxicity as Applied to some Selected Aromatic Compounds

Abstract

In the present chapter, density functional theory based reactivity indices are applied as chemical descriptors in QSAR analysis for ecotoxicological studies on a group of aromatic compounds. Two sets of aromatic compounds have been chosen to model ecotoxicity. First set comprises 97 electron-donor aromatic compounds and 77 electron-acceptor aromatic compounds studied on Tetrahymena pyriformis. The second set consists of 19 chlorophenol compounds studied for Daphnia magna, Brachydanio rerio and Bacillus. It is observed that a very simple descriptor like atom counting (number of non-hydrogenic atoms) along with other descriptors like electrophilicity index and (ground state) energies of the molecule, provide the best QSAR model for the toxicity of the first set of compounds. For the second set of compounds, it is found that the descriptors consisting of atom counting and group philicities together give the best QSAR models.