Design,synthesis, molecular docking,and anticancer activity of benzoxazole derivatives as VEGFR‐2 inhibitors

Novel series of benzoxazole s 4 _a‐f ‐16 were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT‐116, and MCF‐7 cells. HCT‐116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 5 _e was found to be the most potent against HepG2, HCT‐116, and MCF‐7 with IC₅₀ = 4.13 ± 0.2, 6.93 ± 0.3, and 8.67 ± 0.5 µM, respectively. Compounds 5 _c , 5 _f , 6 _b , 5 _d , and 6 _c showed the highest anticancer activities against HepG2 cells with IC₅₀ of 5.93 ± 0.2, 6.58 ± 0.4, 8.10 ± 0.7, 8.75 ± 0.7, and 9.95 ± 0.9 µM, respectively; HCT‐116 cells with IC₅₀ of 7.14 ± 0.4, 9.10 ± 0.8, 7.91 ± 0.6, 9.52 ± 0.5, and 12.48 ± 1.1 µM, respectively; and MCF‐7 cells with IC₅₀ of 8.93 ± 0.6, 10.11 ± 0.9, 12.31 ± 1.0, 9.95 ± 0.8, and 15.70 ± 1.4 µM, respectively, compared with sorafenib as a reference drug with IC₅₀ of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 5 _c‐f and 6 _b,c were further evaluated for their vascular endothelial growth factor receptor‐2 (VEGFR‐2) inhibition. Compounds 5 _e and 5 _c potently inhibited VEGFR‐2 at lower IC₅₀ values of 0.07 ± 0.01 and 0.08 ± 0.01 µM, respectively, compared with sorafenib (IC₅₀ = 0.1 ± 0.02 µM). Compound 5 _f potently inhibited VEGFR‐2 at low IC₅₀ value (0.10 ± 0.02 µM) equipotent to sorafenib. Our design was based on the essential pharmacophoric features of the VEGFR‐2 inhibitor sorafenib. Molecular docking was performed for all compounds to assess their binding pattern and affinity toward the VEGFR‐2 active site.