Synthesis, characterization and anticancer screening of novel phenylbenzylidene thiosemicarbazone derivatives

Ten derivatives of phenylbenzylidene thiosemicarbazones (1–10) were synthesized by multicomponent reaction between hydrazine hydrate, isothiocyanate and substituted aldehydes in the presence of the phase transfer reagent Triton-B and subsequently heating the mixture. The synthesized compounds 1, 2, 5, 8 demonstrated to act as highly potent anticancer agents. They showed anticancer activity by mobilizing cellular ⁵⁹Fe, inhibiting cellular uptake of ⁵⁹Fe from ⁵⁹Fe₂-Tf, and mediating the ascorbate oxidation. Further, the structure activity relationship revealed that the donor atom and its stabilization resulted in better anticancer activity. The softness of the chelating donor atoms N and S yielded redox active iron complexes, which easily mediated ascorbate oxidation. This study identified the selective and potential chelators, which may act as anticancer agents and require further in vivo screening in future.