Rational Design and Synthesis of a Novel Series of Thiosemicarbazone-Containing Quinazoline Derivatives as Potential VEGFR2 Inhibitors.

Background/Objectives: Angiogenesis plays a crucial role in tumor development and is a driving force for the aggressiveness of several types of cancer. Our team developed a novel series of thiosemicarbazone-containing quinazoline derivatives, TSC1-TSC10, as potential VEGFR2 inhibitors with proven anti-angiogenic and antiproliferative potential. Methods: The TSC1-TSC10 series was synthesized and characterized by spectral data. Extensive methodology was applied both in vitro (Alamar Blue assay, Scratch assay, CAM assay, and VEGFR2 kinase assay) and in silico (docking studies, MDs, and MM-PBSA) for the confirmation of the biological potential. Results: TSC10 emerged as the most promising compound, with a favorable cytotoxic potential across the cell panel (Ea.Hy296, HaCaT, and A375) in agreement with the in vitro VEGFR2 kinase assay (IC₅₀ = 119 nM). A comparable motility reduction in the vascular endothelial cells to that of the reference drug sorafenib was provided by TSC10, with a similar anti-angiogenic potential in the more complex in ovo model of the CAM assay. The in silico experiments confirmed the successful accommodation of the active site of the kinase domain similar to sorafenib for the entire TSC1-TSC10 series, providing valuable key insight into the complex stability driving force for the evaluated compounds. Conclusions: The in vitro evaluations of the biological potential correlated with the in silico predictions by computer-aided complex simulations provided a solid confirmation of the initial hypothesis for the TSC1-TSC10 series.