Synthesis, structural characterization and cytoprotective activity of a new mixed oxidovanadium(IV) compound with nitrilotriacetate and imidazole ligands

Abstract

Herein, we have shown that the water molecule in [VO(nta)(H2O)]- can be replaced by an imidazole moiety which is a versatile binding site in various biological systems. These findings offer a new approach for synthesizing mixed ligand complexes with desired physicochemical and biological properties. In this study, a new hetero-ligand oxidovanadium(IV) monohydrate salt was successfully synthesized and structurally characterized. The compound consists of a mononuclear [VO(nta)(im)]- entity, where nitrilotriacetato–(nta) and imidazole (im) ligands are incorporated, along with an imidazolinium counterion, [im(H)][VO(nta)(im)]H2O. To characterize the complex in a solid state, various techniques were employed including elemental analysis, thermogravimetric analysis (TG-FTIR), single-crystal X-ray diffraction method and IR spectroscopy. In addition, the investigation included a study of the speciation of the complex ion [VO(nta)(im)]- in an aqueous solution. Furthermore, the influence of imidazole as an auxiliary ligand (im) in the coordination sphere of V(IV) is investigated in terms of its effects on ABTS+• radical scavenging activity and cytoprotective properties against oxidative damage in the hippocampal neuronal HT22 cell line. Finally, this study compares and discusses the physicochemical properties and biological activities of the newly synthesised compound and those containing [VO(nta)(H2O)]- complex anions.