title: Synthesis of theaflavin from epicatechin and epigallocatechin by plant homogenates and role of epicatechin quinone in the synthesis and degradation of theaflavin.
abstract: Oxidation products of (-)-epicatechin and (-)-epigallocatechin by treatment with homogenates of 62 plants belonging to 49 families were compared. Forty-six plants were capable of synthesizing theaflavin, a black tea pigment, regardless of whether they contained catechins. Loquat, Japanese pear, and blueberry had activities higher than that of fresh tea leaves after 5 h of treatment; furthermore, these plants oxidized theaflavin to theanaphthoquinone. An additional new metabolite, dehydrotheasinensin, was generated on treatment with fresh tea leaves, eggplant, and unripened Japanese orange. Evidence for the oxidation of epigallocatechin and theaflavin by electron transfer to epicatechin quinone was demonstrated in a time course study using bananas and trapping the quinone intermediates as glutathione conjugates.
authors.affiliation: School of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Chie
authors.initials: C
authors.lastname: Mine
authors.forename: Kyoko
authors.initials: K
authors.lastname: Inoue
authors.forename: Miyuki
authors.initials: M
authors.lastname: Matsuda
authors.forename: Isao
authors.initials: I
authors.lastname: Kouno
mesh_terms: D044946:Biflavonoids; D002392:Catechin / Q000031:analogs & derivatives* / Q000378:metabolism*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D028521:Musa / Q000378:metabolism; D010084:Oxidation-Reduction; D010944:Plants / Q000378:metabolism*; D013662:Tea / Q000737:chemistry / Q000378:metabolism
chemical_list: D044946:Biflavonoids; D013662:Tea; C056068:theaflavin; D002392:Catechin; C057580:gallocatechol