Design, Synthesis, and Cytotoxicity Evaluation of Styryl‐Spirooxindole Carboxamides as Potential Tubulin and VEGFR‐2 Dual Inhibitors

In the pursuit of novel therapeutic agents for cancer treatment, a series of styryl-spirooxindole-based carboxamide derivatives are designed and synthesized, targeting dual inhibition of tubulin polymerization and VEGFR-2 kinase. Among the synthesized compounds, 9j demonstrates remarkable potency against A549 (lung cancer) cell line with an IC₅₀ value of 0.89 ± 0.14 μM. The efficacy of 9j is significantly surpassed by that of the standard drugs colchicine (IC₅₀ = 1.66 ± 0.16 μM) and sunitinib (IC₅₀ = 2.98 ± 0.4 μM). Furthermore, compound 9j exhibits 66% growth inhibition in HUVEC cells with an IC₅₀ value of 1.2 ± 0.2 μM, as assessed by the MTT assay. Mechanistic studies confirm the apoptotic activity of compound 9j, as evidenced by its ability to induce mitochondrial dysfunction and promote apoptosis. Further, the apoptosis is quantified through Annexin V/PI dual staining assay. Additionally, enzymatic assays highlight the dual inhibitory activity of 9j against tubulin polymerization (IC₅₀ = 1.1 μM) and VEGFR-2 kinase (IC₅₀ = 0.95 ± 0.5 μM). In continuation, the anti-angiogenic effect of 9j is also evaluated by CAM assay. Moreover, molecular docking studies also reveal critical binding interactions within the active sites of both targets. Pharmacokinetic evaluations using QikProp and SwissADME tools further underscore the drug-like properties of compound 9j, strengthening its potential as a lead molecule. This comprehensive study indicates that compound 9j is a promising lead in the realm of dual-targeting anti-cancer strategies, warranting further development and optimization.