Antitumor activity of manganese(II) and cobalt(III) complexes of 2-acetylpyridine schiff bases derived from S-methyldithiocarbazate: Synthesis, characterization, and crystal structure of the manganese(II) complex of 2-acetylpyridine S-methyldithiocarbazate

Transition metal complexes [Mn(L)2] (I) and [Co(L)2] · (ClO4) · H2O (II), where HL = 2-acetylpyridine S-methyldithiocarbazate, have been synthesized. Complex I was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction studies. The manganese(II) atom in complex I adopts a distorted octahedral geometry with the Schiff base coordinated to it as a uninegatively charged tridentate chelating agent via the pyridine and azomethine nitrogen atoms and the thiolate sulfur atom. Biological studies carried out in vitro against K562 leukemia cancer cell line have shown that the free ligand and its metal complexes exhibited significant and different antitumor activity, since they exhibit IC50 values in the μM range.