Two quercetin-zinc complexes were synthesized according to different ratio reactants, and their biological activities were measured by means of pyrogallol autoxidation. The result shows that they have different level antioxidative activities. Quantum chemistry calculations were performed by using Gaussian 98 program at HF/LanL2DZ basis set. The geometry structures, charges, atomic orbital contribution to frontier molecular orbitals, molecular orbital energies and vibrational frequency were discussed. It indicates that they have good stabilities and relatively high different level antioxidative activities, which is consistent with the experimental result.

Key words: complex, quantum chemistry calculation, antioxidative activity