Elimination of hydrogen peroxide enhances tyrosinase-catalyzed synthesis of theaflavins. (October 2019)

• Record Type: Journal Article
• Authors: Narai-Kanayama, Asako; Uchida, Yuuka; Kawashima, Aya; Nakayama, Tsutomu
• Is Part Of: Process biochemistry. Volume 85(2019)
• Page Start: 19
• Page End: 28
• Publication Date: 2019-10
• Subjects: EC (-)-epicatechin -- EGC (-)-epigallocatechin -- ECg (-)-epicatechin gallate -- EGCg (-)-epigallocatechin gallate -- FOX ferrous ion oxidation -- H2O2 hydrogen peroxide -- PPO polyphenol oxidase -- TF1 theaflavin -- TF2A theaflavin 3-O-gallate -- TF2B theaflavin 3′-O-gallate -- TF3 theaflavin 3, 3′-di-O-gallate; Theaflavin -- Tyrosinase -- Enzymatic synthesis -- Hydrogen peroxide -- Catalase; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2019.07.004
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: During the incubation of each of four catechins with or without tyrosinase, H2 O2 increased in the reaction mixtures. The increments of H2 O2 were different depending on the kind of catechin. H2 O2 produced by auto-oxidation of (-)-epigallocatechin (EGC) and enzymatic oxidation of (-)-epicatechin gallate (ECg) inactivated tyrosinase. Elimination of H2 O2 by the addition of catalase enhanced tyrosinase-catalyzed synthesis of theaflavins from catechins, in particular theaflavin-3′-gallate (TF2B) from ECg and EGC. Abstract: In this study, we found that hydrogen peroxide was generated during the separate incubation of four catechins, (-)-epicatechin, (-)-epigallocatechin, and their galloylated forms, in the absence or presence of mushroom tyrosinase (EC 1.14.18.1). In particular, autooxidation of (-)-epigallocatechin and enzymatic oxidation of (-)-epicatechin gallate contributed to the increase of hydrogen peroxide. We confirmed the hydrogen peroxide-induced inactivation of tyrosinase and found that hydrogen peroxide was also generated during the tyrosinase-catalyzed synthesis of theaflavins by selectively combining two types of catechins, diphenol- and pyrogallol-types. Elimination of hydrogen peroxide by co-incubation with bovine catalase (EC 1.11.1.6) increased the products in synthetic reactions for TF1, TF2A, TF2B, and TF3 by 15%, 16%, 45%, and 18%, respectively. Based on the prospective mechanism of the tyrosinase-catalyzed synthesis of theaflavins, the yield of TF2B increased by elevating the initial ratio of (-)-epigallocatechin/(-)-epicatechin gallate in the reaction media. Furthermore, under such conditions, there were clear ameliorative effects of catalase on the tyrosinase-catalyzed synthesis of TF2B, reaching 3.1-fold increase of the product compared to the reaction without catalase. These results support a novel strategy to use both tyrosinase and catalase for the efficient synthesis of theaflavins from catechins.