3D-QSAR assisted design, synthesis and pharmacological evaluation of novel substituted benzamides as procaspase-3 activators and anticancer agents

Novel substituted benzamides were designed using 3D-QSAR analysis, synthesized and screened using in vitro procaspase-3 kinase activation and MTT assays. For the rational design of the novel compounds, we performed 3D-QSAR study and generated statistically validated CoMFA (q2 = 0.736, r2cv = 0.729) and CoMSIA (q2 = 0.751, r2cv = 0.716) models. Generated contour maps using CoMFA and CoMSIA analysis suggested the requirement of steric bulkiness (aromatic ring) along with small electron-withdrawing groups (-Cl, -diCl, -F) for the design of novel compounds. CoMSIA, HBA, and HBD contour maps also suggested the requirement of functional groups (amide and hydrazide) for hydrogen bonding interactions. A total of 40 novel substituted benzamides were designed, and generated 3D-QSAR models were used for prediction of their activity prior to synthesis. ADMET prediction study was also carried out for the selection of better compounds with no toxicity and better physicochemical parameters for the synthesis. Finally, we synthesised and characterised a total of 10 substituted benzamide derivatives. Synthesized compounds were screened for their anticancer activities, in which compound 14c showed IC50 value of 3.13 µM and 6.01 µM against HT-29 and MDA-MB-231, respectively, compound 7c exhibited excellent anticancer activity with an IC50 value of 3.76 µM and 5/63 µM against HT-29 and MDA-MB-231, respectively. Furthermore, a procaspase-3 kinase activation assay was performed, in which both these compounds (7c, EC50 = 3.12 µM, 12b, EC50 = 2.93 µM and 14C EC50 =2.93) demonstrated activation of enzymatic potency and revealed that the anticancer activity of these compounds may be due to activation of the procaspase-3 enzyme. In vitro screening assays confirmed and validated the computational design of novel benzamide derivatives. Compounds 14c and 7c are our lead compounds for further development as anticancer agents based on the induction of apoptosis through procaspase-3 activation.