Synthesis, characterization, and biological activity of cadmium (II) and antimony (III) complexes based on 2-acetylpyrazine thiosemicarbazones

Two cadmium (II) complexes formulated as [Cd(L-1)(HL1)]ClO4 (Cd1) and [Cd(L-2)(2)] (Cd2), also two antimony (III) complexes formulated as [Sb(L-1)(2)](2)Cl-2 center dot CH3OH (Sb1) and [Sb(L-2)Cl-2] (Sb2) (HL1 = 2-acetylpyrazine N-4- methylthiosemicarbazone, HL2 = 2-acetylpyrazine N-4-dimethylthiosemicarbazone) have been synthesized, and the molecular structure of the four complexes have been determined by single crystal X-ray diffraction. The antimicrobial study has been conducted against E. coil and S. aureus, and the results indicated that the antibacterial activity of Cdl and Sbl increased to some extent than their ligand HL1, while Cd2 and Sb2 presented fairly effective antibacterial activity mainly the same as their ligand HL2. The four compounds all exhibited improved cytotoxic activity against the human hepatocellular carcinoma HepG2 cells than the ligands. While Cd2 displayed the most effective antipmliferative activity, and also the preferable selectivity for HepG2 cells versus normal QSG7701 cells. It is noted that there was a strong relationship between the activity of the ligand HL2 and its cadmium (II) or antimony (III) complexes.