Novel transition metal complexes of 5-methyl-5-(4-nitrophenyle)-hydantoin: Synthesis, characterization, theoretical study and anticancer and antioxidant studies

New Ni(II), Pd(II) and Pt(II) complexes of 5-methyl-5-(4-nitrophenyle)-hydantoin (L) were synthesized and characterized. The new complexes were exactly determined by elemental analysis, FT-IR, 1H NMR, 13C NMR and Mass analysis. Resulting data, offered evidence for coordination of CO-ligand of hydantoin to the Ni(II), Pd(II) and Pt(II), as the metal center. Results from antioxidant activity assay of the compounds Pd(II) and Pt(II) showed their considerable radical scavenging abilities (IC50: 0.15 to 0.23 mg mL-1). Moreover, cytotoxic activity of the compounds Pd(II) and Pt(II) was tested against three different cancer cell lines including MCF-7 (breast), A549 (lung) and AGS (gastric) adenocarcinoma cells. The bonding situation between the [MCl2] and L fragments in [L→PdCL2←L] complexes, were carried out by NBO and energy-decomposition analysis (EDA), as well as its natural orbitals for chemical valence variation (EDA-NOCV). The results show that the M←O bond interaction energies (ΔEint) of the L and MCl2 fragments in 2-4 complexes are substantial and conform to the V-shaped trend for the transition metals of the first, second, and third row as Ni > Pt > Pd.