Abstract: The interactions between chromium cations(Cr2+,Cr3+,Cr6+) and reduced glutathione(GSH) were systematically investigated employing the density functional theory DFT/B3LYP, and the structures of GSH prevalent in both gas and aqueous phases were taken into account. The results showed that:the higher of the charge and smaller of radius of the metal cation are, the larger of the deformation energy of GSH and the binding energy between metal ions and GSH are. The Cr6+ cation might promote the skeleton structure broken and catalyze the decarboxylation reaction of GSH. The interactions between Cr2+ or Cr3+ and GSH in both gas and liquid phase gave nine stable complexes. Comparing with the results gained in gas, the aqueous environment caused a considerable reduction of the binding energies.

Key words: chromium cations, glutathione, Density functional theory