Structural characterization and biological properties of a new dinuclear oxidovanadium(IV) N-(phosphonomethyl)iminodiacetate complex with the 4-amino-2-methylquinolinium cation

Abstract

The crystal and molecular structures of a new dinuclear oxidovanadium(IV) complex with the N-(phosphonomethyl)iminodiacetate (pmida) ligand and the 4-amino-2-methylquinolinium ([amqH]+) cation of the molecular formula [amqH]4[V2O2(pmida)2]6H2O have been determined. The phosphonate groups in the two pmida4− ligands form two bridges between adjacent V4+ atoms, resulting in the formation of a [V2O2(pmida)2]4− dimer with a V2O4P2 eight-membered ring. This is the first example of a quinoline derivative complex containing the [V2O2(pmida)2]4− ion. The susceptibility curve for the complex exhibits a maximum at approximately 10K, indicating the presence of antiferromagnetic interactions transmitted in the crystal lattice. Furthermore, the biological properties of the complex in the concentration range 1–100μM were investigated in relation to its cytoprotective activity against oxidative damage generated exogenously using hydrogen peroxide in the hippocampal neuronal HT22 cell line (MTT tests). The obtained results were subsequently referred to the [amqH][VO(nta)(H2O)]H2O analogue as well as trolox and ascorbic acid, used as known antioxidants. It has been established that the title compound effectively protects HT22 from oxidative damage and is a potentially good candidate for further evaluation of the mechanism of its action.