title: Biomimetic one-pot preparation of a black tea polyphenol theasinensin A from epigallocatechin gallate by treatment with copper(II) chloride and ascorbic acid.
abstract: Chromatographic separation of black tea polyphenols is too difficult to supply sufficient quantities of pure compounds for biological experiments. Thus, facile methods to prepare black tea constituents were desired. Treatment of epigallocatechin gallate with copper(II) chloride efficiently afforded an unstable quinone dimer, dehydrotheasinensin A, and subsequent treatment with ascorbic acid stereoselectively yielded theasinensin A. The latter is a dimer with an R-biphenyl bond, one of the major polyphenols found in black tea. The method is simpler and more effective than enzymatic preparation.
authors: Graduate School of Biomedical Sciences, Nagasaki University, Japan.
authors: Takuya
authors: T
authors: Shii
authors: Makoto
authors: M
authors: Miyamoto
authors: Yosuke
authors: Y
authors: Matsuo
authors: Takashi
authors: T
authors: Tanaka
authors: Isao
authors: I
authors: Kouno
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry; D040761:Biomimetic Materials / Q000138:chemical synthesis* / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D019281:Dimerization; D010084:Oxidation-Reduction; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D059808:Polyphenols / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism; D013662:Tea / Q000737:chemistry*
chemical_list: D001578:Benzopyrans; D010636:Phenols; D059808:Polyphenols; D013662:Tea; C481298:theasinensin A; D003300:Copper; D002392:Catechin; C045651:epigallocatechin gallate; D001205:Ascorbic Acid