Three series of quinoxaline derivatives were synthesized and biologically evaluated against three tumor cell lines (HCT116 human colon carcinoma, HepG2, liver hepatocellular carcinoma and MCF-7, human breast adenocarcinoma cell line), in addition to VEGFR-2enzyme inhibition activity.
Compounds 6c and 6b showed enzyme inhibition of 97% and 87% at 10 µM, respectively, and exhibited potent dose-related VEGFR 2 inhibition with IC<sub>50</sub> values of 0.85 µM and 2.26 µM, respectively.
Enzyme inhibition assay was performed for compound 19 against mTOR (IC<sub>50</sub> = 0.64 μM) and VEGFR-2 (IC<sub>50</sub> = 1.97 μM) to show high potency in comparison to rapamycin (IC<sub>50</sub> = 0.43 μM) and sorafenib (IC<sub>50</sub> = 0.3 μM) as references, respectively.
The in vitro vascular endothelial growth factor receptor (VEGFR) enzyme inhibition assay was carried out for the most active compounds at a single dose of 10 µM.