Synthesis, characterization and anticancer studies of Ni(II), Pd(II) and Pt(II) complexes with Schiff base derived from N-methylhydrazinecarbothioamide and 2-hydroxy-5-methoxy-3-nitrobenzaldehyde

A carbothioamide NSO tridentate Schiff base ligand (HL) and its square planar complexes Na[NiLOAc], Na [PdLOAc] and [PtLdmso] have been synthesized and characterized on the basis of melting point, elemental analysis, FT-IR, H-1 NMR, C-13 NMR, UV-Vis spectra. The structure of HL was elucidated with Xray diffraction analysis. In the present study, the synthesized compounds were evaluated for their anticancer properties against three human cancer cell lines breast cancer (MCF-7), cervical (Hela), and colon (HCT-116). In addition, the cytotoxicity of the synthesized compounds was tested on a normal human cell line (human endothelial cell line EA.hy926). Among the tested compounds, the complex [NIOAc] excelled in halting proliferation of the cervical and colon cancer cells with median inhibitory concentration (IC50) values of 2833 and 34.4 mu M, respectively. The complex, [PdLOAc] demonstrated selective cytotoxicity against breast cancer line MCF-7 with IC50 = 47.5 mu M, while HL showed inhibitory effect against colon cancer cell line (HCT-116) with IC50 = 55.66 M. The complex, [PtLdmso] showed mild activity against breast cancer (MCF-7) and cervical cancer (Hela) cells with IC50 = 64.44 and 68.3 mu M, respectively, whereas, it displayed insignificant cytotoxicity against human endothelial cells (EA.hy926) with IC50 > 200 mu M. Cancer cells treated with [NiLOAc] showed apoptotic features such as membrane blebbing and DNA condensation. Thus, the findings of the present study demonstrated that the series of metal complexes of HL could form the new lead for development of cancer chemotherapies to treat human cervical, breast and colon malignancies. (C) 2016 Elsevier B.V. All rights reserved.