Synthesis, antiproliferative activity and mechanism of gallium(III)-thiosemicarbazone complexes as potential anti-breast cancer agents.

Five thiosemicarbazone ligands were synthesized and characterized by condensation with different aldehydes or ketones by 4-phenylthiosemicarbazone. The representative dichlorido[2-(Di-2-pyridinylmethylene)-Nphenylhydrazinecarbothioamide-N,N,S]-gallium(III) (Ga4) was characterized by X-ray single crystal diffraction, which was 1:1 ligand/Ga(III) complexes. The structure-activity relationship of these ligands and Ga (III) complexes have been investigated, and the results demonstrate that the formation of Ga (III) complexes have significant antiproliferative activity over the corresponding ligands. The anticancer mechanism of gallium (III) complexes has been studied in detail, which is typical agents that effect on the mitochondrial apoptotic pathway. The ability of gallium (III) complexes to inhibit the cell cycle does not enhanced with the increasing concentrations, whereas the ability to promote apoptosis is concentration-dependent.