Quinazoline-oxindole hybrids as angiokinase inhibitors and anticancer agents: Design, synthesis, biological...

Two new sets of quinazoline-oxindole 8a-l and quinazoline-dioxoisoindoline 10a-d hybrids were designed as type II angiokinase inhibitors and anticancer agents. The design strategy was adjusted to account for the quinazoline scaffold's placement in the target kinases' hinge region, where it would form hydrogen bonding and hydrophobic interactions with the important amino acids to stabilize it, and the amide group's occupation in the gate region, which would direct the oxindole scaffold toward the hydrophobic back pocket. The two sets of quinazolines 8a-l and 10a-d displayed pronounced inhibitory activity on VEGFR-2 (IC₅₀ = 0.46-2.20 µM). The quinazoline-oxindole hybrids 8d, 8f, and 8h displayed IC₅₀ = 0.46, 0.49, and 0.49 µM, respectively. Compound 8f demonstrated potent multikinase activity with IC₅₀ values of 0.95 and 0.67 µM against FGFR-1 and BRAF, respectively. Additionally, compound 8f showed significant anticancer activity against National Cancer Institute's cancer cell lines, with GI₅₀ reaching 1.21 µM. Analysis of the impact of compound 8f on the MDA-MB-231 cell line's cell cycle and apoptosis revealed that 8f stalled the cell cycle at the G2/M phase and promoted its necrosis.