Synthesis, evaluation of in vitro cytotoxic activity, and in silico studies of some 3-methylenamino-4(3H)-quinazolone derivatives

Abstract

A series of 3-methylenamino-4(3H)-quinazolone derivatives were synthesized by imine formation reactions of 3-amino-6-chloro-2-phenyl-4(3H)-quinazolone with various substituted aromatic aldehydes at 80 °C for 1–3 hours using the reflux method. Twenty 3-methylenamino-4(3H)-quinazolone derivatives were synthesized with good to excellent yields (66 to 90%). Compound 5 (2-chloro-6-fluorobenzylidene) exhibited good cytotoxic activity against the RD cell line with an IC₅₀ value of 14.65 μM but exhibited weak cytotoxic activity against the MDA-MB-231 cell line (IC₅₀ = 147.70 μM) compared to the reference drug paclitaxel (PTX, IC₅₀ RD = 0.58 μM and IC₅₀ MDA-MB-231 = 0.04 μM). Meanwhile, compounds 6 (benzo[d][1,3]dioxol-5-ylmethylene) and 7 (4-bromo-2-hydroxybenzylidene) showed good cytotoxic activity against MDA-MB-231 with IC₅₀ values of 10.62 and 8.79 μM, respectively. However, these compounds showed weak cytotoxic activity against the RD cell line (IC₅₀ = 50–55 μM). In particular, potential compounds 5, 6, and 7 exhibited weak cytotoxic activity against the normal cell line LLC-PK1 (IC₅₀ = 34.82–60.18 μM) compared to the highly toxic agent PTX (IC₅₀ = 1.31 μM). Furthermore, compounds 5, 6, and 7 showed strong interactions with the EGFR target with binding affinities of −9.6, −10.1, and −9.8 kcal mol⁻¹, respectively, compared to reference drug Gefitinib (−7.8 kcal mol⁻¹). The in silico ADMET results suggested that these potent derivatives possess a good ADMET profile. Therefore, these three compounds are potential candidates for novel cancer drug development, as demonstrated by in vitro and in silico studies.