Discovery of new quinoxaline-2(1H)-one-based anticancer agents targeting VEGFR-2 as inhibitors: Design, synthesis, and anti-proliferative evaluation.

VEGF/VEGFR2 pathway is the crucial therapeutic target in the treatment of cancer. So that, a new series of quinoxaline-2(1H)-one derivatives were designed and synthesized. The synthesized compounds were tested against three human cancer cell lines (HepG-2, MCF-7 and HCT-116) aiming to evaluate its anti-proliferative activities. Doxorubicin as a universal anticancer drug and sorafenib as a potent VEGFR-2 inhibitor were used as positive controls. The data obtained from biological activity were found highly correlated with that obtained from molecular modeling studies. The most sensitive cell line to the influence of our new derivatives was HCT-116. Compounds 13b, 15, 16e and 17b exert the highest cytotoxic activities against the tested cell lines. Overall, compound 15 was the most active member with IC50 values of 5.30, 2.20, 5.50 µM against HepG-2, MCF-7 and HCT-116, respectively. Compounds 15 and 17b showed better anti-proliferative activities than doxorubicin and sorafenib against the three cancer cell lines. Additionally, compound 16e showed better anti-proliferative activities than doxorubicin and sorafenib against HepG-2 and HCT-116 but exhibited lower activity against MCF-7 cell line. In addition, the most promising members were further evaluated for their inhibitory activities against VEGFR-2. Compounds 15 and 17b potently inhibited VEGFR-2 at lower IC50 values of 1.09 and 1.19 µM, respectively, compared to sorafenib (IC50 = 1.27 µM). Moreover, docking studies were conducted to investigate the binding pattern of the synthesized compounds against the prospective molecular target VEGFR-2.