Cytotoxic activities of new iron(III) and nickel(II) chelates of some S-methyl-thiosemicarbazones on K562 and ECV304 cells

The S-methyl-thiosemicarbazones of the 2- hydroxy-R-benzaldehyde (R= H, 3-OH 3-OCH3 or 4-OCH3) reacted with the corresponding aldehydes in the presence of FeCl3 and NiCl2. New ONNO chelates of iron(III) and nickel (II) with hydroxy- or methoxy-substitued N1,N4-diarylidene-Smethyl- thiosemicarbazones were characterized by means of elemental analysis, conductivity and magnetic measurements, UV-Vis, IR and 1H-NMR spectroscopies. Cytotoxic activities of the compounds were determined using K562 chronic myeloid leukemia and ECV304 human endothelial cell lines by MTT assay. It was determined that monochloro N1-4- methoxysalicylidene-N4-4-methoxysalicylidene-S-methylthiosemicarbazidato- iron(III) complex showed selective anti-leukemic effects in K562 cells while has no effect in ECV304 cells in the 0.53 μg/ml (IC50) concentrations. Also, some methoxy-substitued nickel(II) chelates exhibit high cytotoxic activitiy against both of these cell lines in low concentrations. Cytotoxicity data were evaluated depending on cell lines origin and position of the substituents on aromatic rings