catechins

DFT calculations were applied to compare the antioxidant potential of four major catechins present in green tea. The thermodynamic parameters related to three key mechanisms of primary antioxidant action were investigated in detail. Molecular orbital energies, absolute hardness, electronegativity, and electrophilicity index, which contributed to the radical scavenging were also investigated. The radical scavenging potential of each hydroxyl group of these polyphenolic antioxidants were investigated independently.

The reactivity of 18-molybdodiphosphate heteropoly complex (18-MPC) with respect to the polyphenolic compounds contained in green teas was estimated. The one- and two-electron heteropoly blues coexist depending on the ratio of reducing agent to 18-MPC in such reactions. The results for the determination of total content of polyphenols in green teas of different brands obtained with 18-MPC and FolinCiocalteu reagent are close to each other. The disadvantages of the existing methods are shown.