Abstract: Non-crystallization coordination of bioactive ingredients in edible plants can generate new or better pharmacological activity. In this paper, the optimal reaction conditions between dihydromyricetin (DMY) and Cu2+, the effect of coordination on the crystal structure and antioxidant activity of DMY were investigated. Results indicated that the optimal reaction conditions were reaction temperature of 40 ℃, reaction time of 60 min and reaction pH of 9.5. The characteristic absorption peaks were 332 nm for DMY-Cu complex and 292 nm for DMY, which may be ascribed to the oxygen from 4 carbonyl and 5 hydroxyl groups participated in coordination according to FT-IR analysis and theoretical chemical calculation of DMY or its complex. In addition, the scavenging capability of DMY against hydroxyl free radicals (·OH) was increased due to the non-crystallization coordination according to XRD analysis of DMY and its complex.

Key words: DMY, Cu, complex, antioxidation