Efficient Synthesis of Theaflavin 3-Gallate by a Tyrosinase-Catalyzed Reaction with (-)-Epicatechin and (-)-Epigallocatechin Gallate in a 1-Octanol/Buffer Biphasic System

Asako Narai-Kanayama, Yoshinori Uekusa, Fumiyuki Kiuchi, Tsutomu Nakayama

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Theaflavins, the orange-red pigments contained in black tea, have attracted attention as a result of their health-promoting effects. However, their synthetic preparation, in which the enzymatic oxidation of catechol-type catechin is followed by the quinone-induced oxidative dimerization of selectively combined catechol- and pyrogallol-type catechins, provides only a low yield. In the present study, we found that a 1-octanol/buffer biphasic system improved the yield of theaflavin 3-gallate in a tyrosinase-catalyzed synthetic reaction with (-)-epicatechin and (-)-epigallocatechin gallate. When the enzymatic reaction proceeded in a buffer solution, oxidized (-)-epigallocatechin gallate was preferentially used for self-dimerization. However, self-dimerization was suppressed in the octanol phase, allowing oxidized (-)-epigallocatechin gallate to participate in coupling with (-)-epicatechin quinone, leading to effective production of theaflavin 3-gallate. Furthermore, the preferential localization of theaflavin 3-gallate in the octanol phase prevented (-)-epicatechin-quinone-induced degradation.

Original languageEnglish
Pages (from-to)13464-13472
Number of pages9
JournalJournal of Agricultural and Food Chemistry
Volume66
Issue number51
DOIs
Publication statusPublished - 2018 Dec 26

Keywords

  • 1-octanol
  • biphasic system
  • enzymatic synthesis
  • theaflavin
  • tyrosinase

ASJC Scopus subject areas

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

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