Model system-based mechanistic studies of black tea thearubigin formation

Food Chemistry
Ghada H YassinNikolai Kuhnert

Abstract

Thearubigins are the most abundant pigments found in black tea, comprising polyphenolic oxidation products, whose composition and chemical nature have remained unresolved until recently. In the course of studying the mechanism of thearubigin formation from green tea flavan-3-ols, a model system, based on electrochemical oxidation of one of the main tea flavan-3-ol substrates, epigallocatechin gallate (EGCG), was employed. Reaction intermediates and products were subsequently analysed using mass spectrometry techniques, allowing for the identification of key intermediates and products. The results provided, for the first time, spectroscopic evidence for the structures of primary oxidation products, and led to the conclusion that oxidation is mainly taking place on the B-ring and the galloyl group, where the oxidized components undergo oxidative coupling for the formation of theaflavins, theasinensins and polyhydroxylated flavan-3-ols, all precursors for thearubigin formation. Furthermore, density functional theory (DFT) calculations were carried out to support key findings.

References

Jan 26, 1999·Archives of Biochemistry and Biophysics·K KondoM Toyoda
Dec 18, 2001·Journal of Agricultural and Food Chemistry·T TanakaI Kouno
Aug 30, 2003·Phytochemistry·Edwin Haslam
Jul 21, 2006·European Journal of Clinical Nutrition·E J GardnerA R Leeds
Feb 25, 2010·Natural Product Reports·James Warren DrynanNikolai Kuhnert
May 1, 2010·Archives of Biochemistry and Biophysics·Nikolai Kuhnert
Nov 13, 2010·Rapid Communications in Mass Spectrometry : RCM·Nikolai KuhnertMatthias Witt

❮ Previous
Next ❯

Citations

Mar 2, 2016·Molecules : a Journal of Synthetic Chemistry and Natural Product Chemistry·Kazuhiro UchidaEmiko Yanase
Mar 30, 2018·Lipids in Health and Disease·Ali ImranRizwan Munir
Jul 1, 2016·Journal of Food and Drug Analysis·Shu-Yen LinPo-An Chen
May 30, 2020·Critical Reviews in Food Science and Nutrition·Kun ZhuZhonghua Liu
Nov 20, 2018·Journal of Agricultural and Food Chemistry·Xiu-Hua MengYing-Jun Zhang

❮ Previous
Next ❯

Related Concepts

Related Feeds

Cardiovascular Disease Pathophysiology

Cardiovascular disease involves several different processes that contribute to the pathological mechanism, including hyperglycemia, inflammation, atherosclerosis, hypertension and more. Vasculature stability plays a critical role in the development of the disease. Discover the latest research on cardiovascular disease pathophysiology here.