Synthesis, characterization, cytotoxicity, and molecular docking studies of ampyrone-based transition metal complexes

A novel series of mononuclear transition metal complexes, [Cu(L)Cl]1, [Zn(L)Cl]2, [Pd(L)Cl]3, [Cd(L)I]4, [Pt(L)Cl]5, and [Hg(L)Cl]6, was constructed from a pyrazole-derived Schiff ligand,HL, and characterized by physicochemical and spectroscopic methods. Fourier-transform infrared (FT-IR) spectral data showed the studied ligand to be tridentate and coordinated to the metal ions via ONO donor atoms, whereas powder X-ray diffraction (PXRD) analysis revealed the crystalline nature of all the complexes. The in vitro cytotoxicity of the studied ligand and its complexes were tested by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay against the human colorectal cancer cell lines HCT116 and HT29. The results suggested that the HCT116 cell line is highly sensitive to complex1with a half-maximal inhibitory concentration (IC50) of 45.6 mu M, while both cell lines tolerated complexes2and4better in comparison withHL. In addition, complex1with significant anticancer activity was analyzed by molecular docking studies to explore its binding efficacy to the cyclin-dependent kinase 2 active site.