QSAR study on toxicity to aqueous organisms using the PI index

We have attempted to develop quantitative structure-toxicity relationships (QSTRs) to predict hydrophobicity (logP) as well as toxicity (pEC(50) mum) of benzene derivatives using recently introduced Padmakar-Ivan (PI) index. The results have shown that both logP as well as pEC(50) of benzene derivatives can be modelled excellently in multiparametric models in that the PI index and some indicator parameters are involved. The predictive ability of the models is discussed on the basis of the cross-validation method. The superiority of the PI index over several other topological indices is critically examined. (C) 2002 Elsevier Science Ltd. All rights reserved.