Traditional versus WHIM molecular descriptors in QSAR approaches applied to fish toxicity studies

Quantitative structure–activity relationships (QSAR) were performed on nine congenetic aromatic hydrocarbons. Acute response was evaluated in freshwater fish species. QSAR were built by Hanschʹs approaches and weighted holistic invariant molecular (WHIM) indices. The prediction power of QSAR from both approaches was evaluated. Single regression analysis derivated by Hanschʹs approach seem suitable for non-polar compounds. However, for all species, it has not a high predictive power (Q2LOO) of the biological activity from only Kow as molecular descriptor. Multiple regression analysis obtained from WHIM descriptors showed Q2LOO higher than 80%, indicating that molecular descriptors have a prediction power greater than Kow.