Design, synthesis and biological evaluation of spirocyclopropyl oxindole-piperazine/morpholine-based carboxamides as...

Dual-targeting agents represent a promising approach in cancer treatment, offering several significant advantages over traditional single-target therapies or drug combinations. In this connection, herein a series of spirocyclopropyl oxindole-piperazine/morpholine based carboxamides were rationally designed, synthesized, and evaluated for their dual inhibition (tubulin polymerization and VEGFR-2 kinase) activity. Among the synthesized derivatives, compound 8u exhibited potent cytotoxicity against the HepG-2 cell line with an IC₅₀ of 1.88 ± 0.83 μM. Further, VEGFR inhibition assay revealed that the compound 8u inhibited VEGFR-2 kinase with an IC₅₀ of 1.52 ± 0.08 μM, comparable to the standard drug sunitinib (1.2 ± 0.07 μM). Additionally, tubulin polymerization assay demonstrated that 8u inhibited tubulin assembly by 84 %, closely matching the standard colchicine (87 %). Mechanistic studies further indicated that 8u induces intracellular ROS generation and inhibits cell migration. Flowcytometric analysis revealed G0/G1 phase arrest upon treatment with 8u in a dose-dependent manner. Moreover, anti-angiogenic activity was assessed by using a tube formation assay, which showed a significant inhibition at 0.05 μM, exhibiting exponential progression. In addition, Molecular docking, MD simulations and 3D-QSAR studies corroborated the observed activity, while ADME studies confirmed drug-like properties of the compounds. These findings underscore the potential of compound 8u as a promising lead for the development of dual-targeted anticancer agents.