Identification\nof Novel β‑Tubulin Inhibitors\nUsing a Combined <i>In Silico</i>/<i>In Vitro</i> Approach

Abstract

Due to their potential as leads for various therapeutic\napplications,\nincluding as antimitotic and antiparasitic agents, the development\nof tubulin inhibitors offers promise for drug discovery. In this study,\nan <i>in silico</i> pharmacophore-based virtual screening\napproach targeting the colchicine binding site of β-tubulin\nwas employed. Several structure- and ligand-based models for known\ntubulin inhibitors were generated. Compound databases were virtually\nscreened against the models, and prioritized hits from the SPECS compound\nlibrary were tested in an <i>in vitro</i> tubulin polymerization\ninhibition assay for their experimental validation. Out of the 41\nSPECS compounds tested, 11 were active tubulin polymerization inhibitors,\nleading to a prospective true positive hit rate of 26.8%. Two novel\ninhibitors displayed IC₅₀ values in the range of colchicine.\nThe most potent of which was a novel acetamide-bridged benzodiazepine/benzimidazole\nderivative with an IC₅₀ = 2.9 μM. The screening workflow\nled to the identification of diverse inhibitors active at the tubulin\ncolchicine binding site. Thus, the pharmacophore models show promise\nas valuable tools for the discovery of compounds and as potential\nleads for the development of cancer therapeutic agents.