In situ synthesis, crystal structure, selective anticancer and proapoptotic activity of complexes isolated from the system containing zerovalent nickel and pyrazole derivatives

Abstract

New nickel(II) complexes [NiLS(NCS)2]∙CH3CN (1) [Ni(dmpz)2(NCS)2]n (2), where LS is N,N,N-tris(1-(3,5-dimethylpyrazolylmethyl)amine) and dmpz is 3,5-dimethylpyrazole, have been isolated in a one-pot synthesis by reacting zerovalent-powered nickel, 1-hydroxymethyl-3,5-dimethylpyrazole (HL1) and 1-carboxamide-3,5-dimethylpyrazole (HL2) as precursors. The complexes were characterized by elemental analysis, IR and UV–Vis spectra, thermal investigations and single crystal diffraction studies. The anti-proliferative activity of the described Ni(II) complexes was studied in vitro against selected human tumour cell lines and normal human cells (fibroblasts). The monomeric complex [NiLS(NCS)2]∙CH3CN (1) expressed more potent anti-proliferative activity towards cancer cells with the relevant cytotoxicity, while the polymeric complex [Ni(dmpz)2(NCS)2]n (2) was very toxic towards normal cells and was also characterized by mild inhibitory potency against tumour cells and poor selectivity. Complex (1) causes massive death of cancer cells due to programmed cell death, apoptosis. The obtained results demonstrated potent cytotoxic activity of the isolated [NiLS(NCS)2]∙CH3CN complex combined with strong selectivity towards cancer cells, and the mechanism of its actions included apoptosis.