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)-2 H -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 complex 1 with a half-maximal inhibitory concentration (IC 50 ) of 45.6 μM, while both cell lines tolerated complexes 2 and 4 better in comparison with HL . In addition, complex 1 with significant anticancer activity was analyzed by molecular docking studies to explore its binding efficacy to the cyclin-dependent kinase 2 active site.