Predictive QSAR models estimating ecotoxic hazard of phenylureas - aquatic toxicity

Quantitative structure-activity relationships (QSARs) are analyzed for evaluating phenylureas side effects. Satisfactory estimates of their fish toxicity can be obtained using an equation derived with chemicals of similar polarity and reactivity using log PsubOW as the only regressor. Algae toxicity for this class of herbicidal compounds does not reflect unspecific effects on aquatic biota, but is overruled by interaction with the electron transport chain in photosystem 2 and can be modelled by QSAR equations describing the Hill reaction inhibition.