Application of the replacement method as a novel variable selection strategy in QSAR. 1. Carcinogenic potential

The carcinogenic potency (TD50) of a set of 62 nitrosocompounds is predicted, applying the QSAR theory. Around thousands of molecular descriptors obtained from the DRAGON 2.1 software are used in order to model the toxicological property bioassay in female rat and considering the water as route of administration. For building the regression model three different methods of variable selection are used, namely the Forward Stepwise Regression, the Genetics Algorithms, and an alternative of the Elimination Method: the Replacement Method. The Replacement Method is used, for the first time, to predict the carcinogenic potency, achieving the best results. The best obtained model had seven variables and it was able to explain 84.3% of the experimental variance after removing 6 chemicals, which are considered as outliers.