Metal chelating ability and antioxidant properties of Curcumin-metal complexes - A DFT approach

Curcumin, a well-documented phytochemical compound used to treat various diseases because of its more tolerability in the human body and has no side effects. The present study describes the metal chelating ability of Curcumin for Mn²⁺, Fe²⁺ and Zn²⁺ metal ions and their antioxidant properties using density functional theory in both gas and DMSO solvent phases. Results reveal that the carbonyl group at diketo moiety is destabilized due to the metal ion coordination. The interaction energies reveal that CurEN-Zn²⁺ are the most stable rather than the CurEN-Mn²⁺ and CurEN-Fe²⁺ complexes. The AIM analysis confirms that the interaction between the metal ions and Curcumin are to be electrostatic dominant. The HOMO-LUMO orbital analysis shows that the charge transfer interaction is dominant for CurEN-Mn²⁺ and CurEN-Fe²⁺ complexes. The DMSO solvent interactions decrease the stability of the CurEN-M²⁺ cation complexes. The antioxidant mechanism is more reactive for metal complexes than the isolated Curcumin. Since Curcumin possess both metal chelating and antioxidant properties, it can be used in chelation therapy for the cure of Alzheimer's disease.