DSpace university logo mark
Advanced Search
Japanese | English 

NAOSITE : Nagasaki University's Academic Output SITE > School of Pharmaceutical Sciences > Articles in academic journal >

Structures of enzymatic oxidation products of epigallocatechin


File Description SizeFormat
Tetra69_8952.pdf447.39 kBAdobe PDFView/Open

Title: Structures of enzymatic oxidation products of epigallocatechin
Authors: Matsuo, Yosuke / Hayashi, Toshimi / Saito, Yoshinori / Kouno, Isao / Tanaka, Takashi
Issue Date: 21-Oct-2013
Publisher: Elsevier Limited
Citation: Tetrahedron, 69(42), pp.8952-8958; 2013
Abstract: To understand the structures of uncharacterized black tea polyphenols, the oxidation products of (-)-epigallocatechin were investigated. Enzymatic oxidation and subsequent heating of the reaction mixture afforded four new oxidation products (6, and 9-11) along with theasinensins C (4) and E (5), dehydrotheasinensin E (12), epitheaflagallin, hydroxytheaflavin, and desgalloyl oolongtheanin. The structures of the new compounds were determined chemically and spectroscopically. Isotheasinensin E (6) is a C-2 epimer of 5, and compounds 9 and 10 are oxidation products of 12. Another new compound, 11, is a yellow pigment and presumed to be a degradation product of proepitheaflagallin. The results disclosed new oxidation mechanisms that occur during black tea production.
Keywords: Black tea / Epigallocatechin / Oxidation / Thearubigins / Theasinensins
URI: http://hdl.handle.net/10069/33913
ISSN: 00404020
DOI: 10.1016/j.tet.2013.07.045
Rights: © 2013 Elsevier Ltd. All rights reserved. / NOTICE: this is the author’s version of a work that was accepted for publication in Tetrahedron. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Tetrahedron, 69, 42(2013)
Type: Journal Article
Text Version: author
Appears in Collections:Articles in academic journal

Citable URI : http://hdl.handle.net/10069/33913

All items in NAOSITE are protected by copyright, with all rights reserved.

 

Valid XHTML 1.0! Copyright © 2006-2015 Nagasaki University Library - Feedback Powerd by DSpace