Comparison of structure-activity relationships derived from two methods for estimating octanol-water partition coefficients.

This study examines several established linear relationships between 96-hour acute toxicity to fish (as log LC50) and octanol-water partition coefficient (as log Kow) with regard to the effect of using a different method of calculating log Kow. For all seven classes of compounds examined here, the linear equation parameters, viz., slope, intercept, r2, and standard error of the estimated log LC50, were about the same for the two methods. As expected, the accuracies of predictions for individual compounds were often different for the two methods, but seldom remarkably so.