A new catechin oxidation product and polymeric polyphenols of post-fermented tea

He Yuan Jiang, Takuya Shii, Yosuke Matsuo, Takashi Tanaka*, Zhi Hong JIANG, Isao Kouno

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

75 Citations (Scopus)


A new epicatechin oxidation product with a 3,6-dihydro-6-oxo-2H-pyran-2- carboxylic acid moiety was isolated from a commercially available post-fermented tea that is produced by microbial fermentation of green tea. The structure of this product was determined by spectroscopic methods. A production mechanism that includes the oxygenative cleavage of the catechol B-ring of (-)-epicatechin is proposed. In addition, polymeric polyphenols were separated from the post-fermented tea and partially characterised by 13C NMR spectroscopy and gel-permeation chromatography. The polymers appear to be primarily composed of epigalloacetechin-3-O-gallate and the molecular weight (Mn) of the acetylated form was estimated to be ∼3500.

Original languageEnglish
Pages (from-to)830-836
Number of pages7
JournalFood Chemistry
Issue number3
Publication statusPublished - 1 Dec 2011

Scopus Subject Areas

  • Analytical Chemistry
  • Food Science

User-Defined Keywords

  • Catechin
  • Oxidation
  • Polyphenol
  • Post-fermented tea
  • Tea


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