Design, synthesis, biological evaluation and in-silico study of thioether-linked 4-hydroxycoumarin-benzothiazole derivatives targeting EGFR for cancer therapy

Abstract Non-small cell lung cancer (NSCLC) remains the most prevalent and fatal subtype of lung cancer, with resistance to current EGFR inhibitors posing a major therapeutic challenge. In this study, a novel series of chromone–benzothiazole hybrids ( 4a–4d ) was designed, synthesized, and evaluated as potential EGFR-targeting anticancer agents. The Knoevenagel condensation method enabled efficient one-pot synthesis using L-proline as a green catalyst. All compounds were characterized by FT-IR, NMR, and HRMS. Molecular docking against EGFR (PDB ID: 3W2O) showed superior binding affinities compared to Erlotinib and 5-FU, with 4d exhibiting the strongest interaction (–8.2 kcal/mol) via π–π stacking and π–sulfur interactions. In silico ADMET analysis predicted good absorption, low CNS permeability, moderate clearance, and acceptable toxicity profiles. In vitro cytotoxicity (MTT assay on A549 lung cancer cells) revealed dose-dependent anti-proliferative effects, with 4d showing the highest efficacy (IC₅₀ = 40.53 µg/mL), closely comparable to 5-fluorouracil (IC₅₀ = 38.12 µg/mL). Structure–activity relationship (SAR) analysis indicated that para-substituted electron-withdrawing groups enhance EGFR affinity, while hydroxyl and methoxy groups improve pharmacokinetics. Overall, 4d emerged as a promising lead for further development as a targeted EGFR inhibitor for NSCLC therapy. Graphical Abstract