Characterization of the binding affinity between some anti-Parkinson agents and Mn2+, Fe3+ and Zn2+ metal ions: A DFT insight

Abstract

In the current work, density functional theory calculations were carried out to evaluate the potential ability of apomorphine, dopamine, hinokitiol and deferiprone chelating agents to coordinate Mn2+, Fe3+ and Zn2+ metal ions with a 1:1 ratio in water solution. The binding energy values reveal that Zn2+/chelating agent complexes are more stable compared to Mn2+/chelating agent and Fe3+/chelating agent complexes. In order to evaluate the parameters that describe the affinity between the metal ions and chelating agents, the metal ion/chelating agent interactions were analyzed by CDA, NBO, QTAIM, FMO analyses. Interestingly, it was found that the FeO interactions in all complexes and MnO interactions in [Mn-DFP]+ complex are mainly electrostatic, whereas other interactions have a covalent character. Moreover, TD-DFT studies showed n → π* and π → π* transitions in the absorption spectra of the complexes.