Laccase‐catalyzed Synthesis and Antioxidant Property of Poly(catechin)

Abstract Catechin was oxidatively polymerized by laccase in a mixture of a polar organic solvent and buffer to give a new class of flavonoid polymers. Myceliophthora laccase showed high catalytic activity for the polymerization. Using a mixed solvent of acetone and pH 5 acetate buffer efficiently produced the polymer. Under the selected conditions, DMF‐soluble polymers were obtained in good yields. Effects of reaction parameters on the yield, solubility, and molecular weight of the polymer have been systematically investigated. A radical species was detected in the polymer by ESR spectroscopy. The polymers showed greatly amplified superoxide scavenging activity and xanthine oxidase inhibitory activity compared with monomeric catechin. Superoxide scavenging activity of poly(catechin)s, n = 3. ○: catechin, □: poly(catechin). magnified image Superoxide scavenging activity of poly(catechin)s, n = 3. ○: catechin, □: poly(catechin).