Rational in silico design and synthetic route elaboration for anti-RCC benzimidazole candidates

Abstract

Benzimidazole continues to be an intriguing scaffold in recent drug discovery, owing to its broad spectrum of pharmacological effects. In recent years, a variety of its derivatives, which included chalcone imines, hydrazones, and thiosemicarbazones, were actively investigated for their antitumor potential. In the search for new agents capable of treating kidney cancer, an analysis of a small series of 2-substituted benzimidazoles (45) using 3D-QSAR modelling was performed to determine the antiproliferative activities against cancer cell lines A-498. The biological activity was sufficient to establish a meaningful structure–activity relationship, providing a foundation for the design of more potent compounds. The activity-favouring and activity-disfavoring structural regions were clearly revealed using contour maps generated by the models. The CoMSIA/SHD model was one of the best developed, and its high statistical robustness (q2 = 0.751) and predictive power (R2 pred = 0.924) indicated its reliability. We designed five new derivatives of benzimidazole based on the QSAR results, which demonstrated potent inhibitory potential. Molecular docking studies were performed in order to investigate in detail their interaction modes with the aromatic receptor, and stable binding conformations at the active site have been found. The in silico pharmacokinetic studies suggested that these compounds have a favourable ADMET and bioavailability profile, reinforcing their suitability for in vitro testing. Two leads, L15 and L22, with better PKs properties and high-predicted activities, were subjected to a 100-ns MD simulation in complex with the aromatase target to investigate their stability. We also conducted a retrosynthetic analysis for L15 and L22, suggesting potential synthetic routes for experimental validation. Overall, these findings suggest that benzimidazole analogues could be promising candidates for treating RCC and possibly for blocking aromatase.