Discovery of novel VEGFR-2 inhibitors. Part II: biphenyl urea incorporated with salicylaldoxime.

A series of novel VEGFR-2 inhibitors containing oxime as hinge binding fragment were described. A strategy of pseudo six-membered ring formed through intramolecular hydrogen bond was employed to mimic the planar quinazoline. The oxime group was firstly introduced to interact with hinge region of VEGFR-2. Most of compounds tested showed moderate to high VEGFR-2 inhibitory activity. In particular, 12l, 12p and 12y exhibited significant enzymatic inhibitory activity as well as potent antiproliferative activity against cancer cells. Molecular docking suggested that the salicylaldoxime formed two hydrogen bonds with hinge region. These biphenylureas could serve as promising lead compounds for developing novel anticancer agents.