Design, synthesis and in vitro anti-proliferative activity of 4,6-quinazolinediamines as potent EGFR-TK inhibitors.

4-Anilino-6-substituted-quinazolines were designed, synthesized and evaluated for EGFR-TK and tumor growth inhibitory activities. The target compounds were designed with enamine ester or urea moieties appended at the C-6 of quinazoline as additional hydrogen bond acceptor functions. Most of the synthesized compounds displayed potent EGFR-TK inhibitory activity at 10 μM and the 6-ureido-anilinoquinazoline derivative 7a showed IC50 value of 0.061 μM. Moreover, six compounds were tested by National Cancer Institute (NCI), USA for their anti-proliferative activity at 10 μM in full NCI 60 cell panel. Compound 7a was further assayed for five dose molar ranges in full NCI 60 cell panel and exhibited remarkable growth inhibitory activity pattern against Non-Small Cell Lung Cancer EKVX (GI50 = 0.37 μM), NCI-H322M (GI50 = 0.36 μM), Renal Cancer A498 (GI50 = 0.46 μM), TK-10 (GI50 = 0.99 μM) and Breast Cancer MDA-MB-468 (GI50 = 1.096 μM) which are of high EGFR expression. Docking study was performed for the active compounds into ATP binding site of EGFR-TK which showed similar binding mode to gefitinib and additional binding with Cys-773 at the gatekeeper of EGFR-TK enzyme.