Design and synthesis of novel pyridopyrimidine derivatives with anchoring non-coplanar aromatic extensions of EGFR inhibitory activity.

The present study describes the synthesis of three series of 4-substituted pyridopyrimidin derivatives 4a-h, 5a-d. 6a-d, starting from 2-amino-6-(4-methoxyphenyl)-4-(4-(substituted) phenyl)nicotinonitrile 2a-d via the reaction with N,N-dimethyl-N-' substituted phenyl formimidamide to obtain 4a-h or with either phenyl isothiocyanate 1:1 and 1:2 to obtain 5a-d, 6a-d respectively. The synthesized compounds were evaluated for their effectiveness as EGFR inhibitors against Gefitinib. Six compounds; 4b,g,h, 5c and 6a,d prompted significantly higher EGFR inhibitory activity relative to that of Gefitinib. While two compounds 4d and 4f showed IC values non-significantly different from that of the reference drug. Furthermore, compounds 4a, 4 h, 6a and 6d were chosen to be assessed in vitro for their cytotoxicity against two EGFR-overexpressing cell lines; two human cancer cell lines namely: MCF7 and MDA-MB-361. Moreover, cell cycle analysis and apoptotic assay was applied for compound 4b that showed most potent inhibitory activity on EGFR, and the highest cytotoxicity against MCF7 and MDA-MB-361, where cell cycle arrest was achieved at pre G and S phases with increased apoptosis. Additionally, a molecular docking study was achieved to inspect the interaction of this compound with the active site of EGFR-TK.