Profiling Acute Oral and Inhalation Toxicity Data Using a Computational Workflow to Screen for Facile Chemical Reactivity

Abstract

Abstract We are developing computational approaches for mechanisms of acute toxicity. Facile chemical reactivity involves formation of covalent adducts between electrophiles and nucleophiles and can be molecular initiating events for adverse outcome pathways. Using an open-source Konstanz Information Miner workflow, we developed a profiler to identify reactive moieties that covers five chemically facile-reactive classes: (1) Michael acceptors, (2) Schiff base formation, (3) acylation, (4) nucleophilic aromatic substitution, and (5) bimolecular nucleophilic substitution. We hypothesized that nonspecific chemical reactivity may be a more prominent molecular initiating event for high acute toxicity for inhalation compared to oral exposure routes because of ensuing respiratory irritation with pulmonary edema resulting in lethality. We tested this hypothesis by stratifying rodent acute oral and 4-hour inhalation toxicity databases (DBs) according to the globally harmonized system (GHS) classification and our p...