ToxDelta: A New Program to Assess How Dissimilarity Affects the Effect of Chemical Substances

Abstract

ToxDelta is a new tool for the evaluation of the toxicity of chemicals based on a modified version of the fmcs_R package. Two structurally similar molecules share a maximum common substructure (MCS). In order to evaluate if two similar molecules have different effects, we focused our attention on the molecular fragments which are not in the MCS. These parts may increase or decrease the value of the property. We considered a variation of the MCS concept of efficient relevance in toxicity assessment where the rings of molecules must not be broken. To assess the toxicity of the target chemical, ToxDelta extracts the MCS and delineates the remaining fragments. Each of these moieties represents a difference between two molecules and its relevance in the toxicity assessment is evaluated against a knowledge-based list of active and inactive fragments. ToxDelta considers the dissimilarities of the molecules in a read across approach.