Theanaphthoquinone, a novel pigment oxidatively derived from theaflavin during tea-fermentation

Tanaka, Takashi; Betsumiya, Yayoi; Mine, Chie; Kouno, Isao

doi:10.1039/b003510f

Cited by 49 publications

(47 citation statements)

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“…2). The structure of this yellow pigment was established by two-dimensional NMR spectroscopic analysis and the chemical derivatization (Tanaka et al, 2000), and the oxidation mechanism of the formation of 7 from 5 was deduced as shown in Fig 3. In this mechanism, the epicatechin quinone (1a) was responsible for the initial oxidation of the benzotropolone ring of 5 (Tanaka et al, 2002a). In addition, two new oxidation products of 5, bistheaflavin A (8) (Tanaka et al, 2001) and dehydrotheaflavin (9) (Tanaka et al, 2002b) were isolated in similar model fermentation experiments using banana and tea leaf homogenates, respectively.…”

Section: Production and Oxidation Of Theaflavinsmentioning

confidence: 99%

Oxidation of Tea Catechins: Chemical Structures and Reaction Mechanism

Tanaka

Kouno

2003

FSTR

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107

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Black tea accounts for almost 80% of the world's tea production and is the most important source of polyphenol in the world. However, little has been known about the chemistry of black tea polyphenols due to their complexity. Since most of the black tea polyphenols are produced by enzymatic oxidation of green tea catechins, in vitro model fermentation experiments using purified catechins are very useful, and recently structures of some novel oxidation products of theaflavins, black tea pigments, have been elucidated. In addition, accumulation of unstable dimer quinones of epigallocatechin and its gallate during tea fermentation has been demonstrated, and the dimer quinones are converted to theasinensins, another major polyphenol characteristic of black tea, on heating. Formation and degradation of theaflavins and epigallocatechin dimer quinones are major pathways in catechin oxidation during tea fermentation and understanding the chemical mechanism is important in clarifying black tea polyphenols.

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Section: Production and Oxidation Of Theaflavinsmentioning

confidence: 99%

Oxidation of Tea Catechins: Chemical Structures and Reaction Mechanism

Tanaka

Kouno

2003

FSTR

Self Cite

107

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“…The dark brown cannot be explained by the presence of a proanthocyanidin polymer or a simple polymer with interflavonoid linkages of A-ring to B-ring and B-ring to B-ring. Although it was not clearly proved, we speculate that benzotropolone [26][27][28][29] and naphthoquinone structures 30) are present as chromophores in those polymers.…”

Section: Properties Of Mafs From Oolong Tea and Black Teamentioning

confidence: 96%

High-Molecular-Weight Polyphenols from Oolong Tea and Black Tea: Purification, Some Properties, and Role in Increasing Mitochondrial Membrane Potential

Fujihara

Nakagawa-Izumi

Ozawa

et al. 2007

Bioscience, Biotechnology, and Biochemistry

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High-molecular-weight polyphenols from oolong and black teas increased mitochondrial membrane potential, as measured by a method using ciliated protozoan Tetrahymena and rhodamine 123. These polyphenols, referred to as mitochondrial activation factors (MAFs), were purified from oolong and black teas by solvent extraction and Toyopearl column chromatography. The number-average molecular weights of the MAFs were 9,000 to 18,000, and the weight-average molecular weights were 15,000 to 25,000. The MAFs increased the mitochondrial membrane potential more than catechins did. Treatment of the MAFs with tannase indicated that they contained galloyl residues. When the MAFs were hydrolyzed with HCl-n-BuOH, cyanidin and delphinidin were detected. The partial structure of the MAFs was analyzed by pyrolysis-gas chromatography-mass spectrometry, and nine compounds were identified. These results suggest that MAFs are heterogeneous polymers of flavan-3-ols and flavan-3-ol gallates with intermonomeric linkages of B-ring to B-ring and C-ring to A-ring.

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“…These approaches included the utilization of potassium ferricyanide as a catalyst in chemical oxidation along with enzymatic oxidation [33,39]. Enzymatic oxidation approaches entail the exploitation of endogenous enzymes in liquid plant extracts or crude tea leaves containing PPO [27,33], peroxidase-containing cultured plant cells such as cultured tea cells [34] and homogenates of various fruits [36]. Many fruit homogenates are capable of synthesising theaflavins, and the mechanism was suggested to be similar to that present in tea fermentation.…”

Section: Introductionmentioning

confidence: 99%

Alternative pathway implicated as an influencing factor in the synthesis of theaflavin

Westhuizen

Steenkamp

et al. 2015

Biocatalysis and Biotransformation

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The principal pigments present in black tea, theaflavins, have been indicated to be of potential clinical significance in various fields of research which has been hampered by the very low levels of theaflavins from black tea extractions, being the original method employed to acquire theaflavins. Forelle pear (44 µM Theaflavin/g dry weight/hr) and Yacon leaf (65 µM Theaflavin/g dry weight/hr) homogenates were tested for their theaflavin synthesis capacity and found to have a larger theaflavin synthesis capacity than a green tea leaf homogenate (26 µM Theaflavin/g dry weight/hr) based upon the flavognost method. In an incubation system of green tea leaf extract utilizing endogenous enzymes present in Forelle pear and Yacon homogenates to synthesise theaflavin, the formation of an unknown peak (m/z 563.1349; (23.95) 5 ; C 26 H 28 O 14 ) was detected by mass spectrometry with a molecular mass similar to theaflavin. This is in contrast to theaflavin being solely synthesised in an in vitro model incubation system using isolated catechins and purified Forelle pear polyphenol oxidase. The preferential formation of the unknown compound could explain the low levels of theaflavins in black tea.

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Theanaphthoquinone, a novel pigment oxidatively derived from theaflavin during tea-fermentation

Abstract: Treatment of a mixture of epicatechin and epigallocatechin with extracts of fresh tea leaf or banana fruit generated a new pigment named theanaphthoquinone, which has a 1,2-naphthoquinone moiety oxidatively derived from the benzotropolone unit of theaflavin.

Cited by 49 publications

References 1 publication

Oxidation of Tea Catechins: Chemical Structures and Reaction Mechanism

Oxidation of Tea Catechins: Chemical Structures and Reaction Mechanism

High-Molecular-Weight Polyphenols from Oolong Tea and Black Tea: Purification, Some Properties, and Role in Increasing Mitochondrial Membrane Potential

Alternative pathway implicated as an influencing factor in the synthesis of theaflavin

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