Synthesis of Co(II), Ni(II) Complexes Containing Aromatic Amines and Glycylglycine with Superoxide Dismutase-like Activity

Six metal complexes were synthesized by the reaction of Co(II), Ni(II) nitrate with the first ligand of Glycylglycine (Gly-gly) and the second ligand of 2,2′-bipyridine (2,2′-bpy)/4,4′-bipyridine (4,4′-bpy)/1,10-phenanthroline (Phen) in water solution (pH = 8.0–8.2). The compositions of these complexes were characterized by elemental analysis, thermal gravimetric analysis-differential thermal analysis (TG/DTA), infrared spectral (IR) method, and nuclear magnetic resonance (1H NMR) method. The superoxide dismutase (SOD)-like activities and the interaction with human serum albumin (HSA) of these complexes were investigated. The results showed that all of the Co(II), Ni(II) complexes had the composition of [M(Gly-gly)(2,2′-bpy/Phen)(H2O)]·2H2O and [M2(Gly-gly)2(4,4′-bpy)(H2O)4]·4H2O. Meanwhile, the IC50 of the complexes was about 0.327–0.564 μM that means the complexes have good SOD-like activities. The fluorescence spectra showed that these complexes could combine with HSA and be delivered by HSA molecules in human blood.

Graphical abstractThe IC50 of the six complexes of Co(II), Ni(II) with the ligand of Glycylglycine (Gly-gly) and 2,2′-bpy/4,4′-bpy/Phen was about 0.327–0.564 μM, meaning the complexes have good SOD-like activities. The fluorescence spectra showed that these complexes could combine with HSA and be delivered by HSA molecules in human blood.Figure optionsDownload full-size imageDownload as PowerPoint slide