Design and synthesis of novel substituted quinazoline-4-one derivatives along with computational and biological evaluation

A series of quinazoline-based 2-((4-methylbenzyl)thio)-3-phenylquinazolin-4(3H)-one derivatives (5a–5h) were synthesized through a two-step procedure. The structures of the final products were verified through a range of spectroscopic techniques. The antiproliferative effect of these novel obtained derivatives was assessed toward two cancer cell lines, MCF-7 and SW480, by the MTT assay, with Cisplatin and Erlotinib as reference drugs. The findings indicated that most of the synthesized molecules showed notable antiproliferative impact on the MCF-7 cell line. Among them, 5c exhibited the strongest activity, displaying an IC50 value of 4.25 ± 1.62 μM toward MCF-7. Remarkably, this compound also demonstrated considerable inhibitory potential against SW480 cells. To elucidate the mechanism of cell death stimulated by the most promising analog (5c), dual staining with Annexin V and PI was carried out for analysis. The results revealed a concentration-dependent increase in Annexin V–positive cells, confirming the ability of compound 5c to trigger apoptosis. Molecular docking simulations were performed to explore the interactions involved in binding between the newly synthesized derivatives and the thymidylate synthase enzyme, showing that the active molecules properly occupied the enzyme's binding pocket. Molecular dynamics simulations were subsequently executed for compounds 5c and 5e representing the most potent and least potent members of the series using the Gaussian 09 software package. Finally, DFT calculations were conducted to theoretically examine the chemical reactivity and stability of the synthesized structures.