Design, synthesis and docking study of novel picolinamide derivatives as anticancer agents and VEGFR-2 inhibitors

Two series of picolinamide derivatives bearing (thio)urea and dithiocarbamate moieties were designed and synthesized as VEGFR-2 kinase inhibitors. All the new compounds were screened for their cytotoxic activity against A549 cancer cell line and VEGFR-2 inhibitory activity. Compounds 7h, 9a and 9l showed potent inhibitory activity against VEGFR-2 kinase with IC₅₀ values of 87, 27 and 94 nM, respectively in comparison to sorafenib (IC₅₀ = 180 nM) as a reference. Compounds 7h, 9a and 9l were further screened for their antitumor activity against specific resistant human cancer cell lines from different origins (Panc-1, OVCAR-3, HT29 and 786-O cell lines) where compound 7h showed significant cell death in most of them. Multi-kinase inhibition assays were performed for the most potent VEGFR-2 inhibitors where compound 7h showed enhanced potency towards EGFR, HER-2, c-MET and MER kinases. Cell cycle analysis of A549 cells treated with 9a showed cell cycle arrest at G2/M phase and pro-apoptotic activity as indicated by annexin V-FITC staining.