title: Three New Oxidation Products Produced from Epigallocatechin-3- O-gallate and Epicatechin-3-O-gallate.
abstract: During chemical studies on uncharacterized black tea polyphenols, the enzymatic oxidation of a mixture of epigallocatechin-3-O-gallate (1) and epicatechin-3-O-gallate (2) was examined, and three new dimeric products together with six known catechin dimers were isolated. Two of the new compounds have tricyclo[5.2.2.0²,⁶]undecane and tricyclo[5.2.1.0²,⁶]decane carboxyl structures generated by oxidative coupling between two pyrogallol-B-rings of 1. Another new product was a dimer connected by a C-C bond between the B-ring of 1 and a galloyl group of 2.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Saito
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction
chemical_list: D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate