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 imageSuperoxide scavenging activity of poly(catechin)s, n = 3. ○: catechin, □: poly(catechin).

Artificial Polymeric Flavonoids: Synthesis and Applications

“…[44] The laccase catalyzed synthesized poly(catechin) also showed excellent antioxidant properties. [45] As described above, catechin showed pro-oxidant properties at concentrations lower than 300 Â 10 À6 M. These results demonstrate that the enzymatically synthesized poly(catechin) possessed a much higher potential for superoxide anion scavenging, when compared with intact catechin. Furthermore, the enzymatically synthesized poly(catechin) also showed much greater inhibition activity against LDL oxidation in a concentration dependent manner, compared to the catechin monomer.…”

“…[44] In the polymerization of catechin using laccase derived from Myceliophthora (ML) as a catalyst, the reaction conditions were examined in detail. [45] ML was reported to show high catalytic activity for the oxidative polymerization of phenol derivatives. [46] A mixture of acetone and acetate buffer (pH 5) was suitable for the efficient synthesis of soluble poly(catechin) with a high molecular weight.…”

“…[47] The XO inhibition effect of the enzymatically synthesized poly(catechin) increased with increasing concentration of catechin units, while the monomeric catechin showed an almost negligible inhibition effect in the same concentration range. [44,45] This markedly amplified XO inhibition activity of poly(catechin) was considered to be due to effective multivalent interaction between XO and the condensed catechin units in the poly (catechin). PolyEGCG also showed an excellent inhibition effect for XO.…”

Enzymatic modification of 2,6-dimethoxyphenol for the synthesis of dimers with high antioxidant capacity

“…Laccases (benzenediol: oxygen oxidoreductase, EC 1.10.3.2) are multi-coppercontaining enzymes which reduce molecular oxygen to water and simultaneously perform oneelectron oxidation of various substrates such as diphenols, methoxy-substituted monophenols and aromatic and aliphatic amines [18]. Laccases have been reported to catalyze the oligomerisation or polymerization of many phenolic compounds as a way of increasing antioxidant capacity [19][20][21].…”

Enzymatic Polymerization of Phenolic Monomers

“…In the polymerization of catechin by using laccase (ML) as catalyst, the reaction conditions were examined in detail [112] . A mixture of acetone and acetate buffer (pH 5) was suitable for the effi cient synthesis of soluble poly(catechin) with high molecular weight.…”