New black tea polyphenol having -ethyl-2-pyrrolidinone moiety derived from tea amino acid theanine: isolation, characterization and partial synthesis

Tanaka, Takashi; Watarumi, Sayaka; Fujieda, Miho; Kouno, Isao

doi:10.1016/j.foodchem.2004.09.013

Cited by 63 publications

(68 citation statements)

References 20 publications

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“…It was isolated from black tea, Camellia sinensis (L.) Kuntze, Theaceae [31]. It has been hypothesized that the Strecker aldehydes of tea amino acids, such as L-theanine, may be formed during the drying and enzyme deactivation stages of black tea production.…”

Section: Resultsmentioning

confidence: 99%

Chromone and Flavonoid Alkaloids: Occurrence and Bioactivity

2011

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The chromone and flavonoid alkaloids represent an unusual group of structurally diverse secondary metabolites, derived from the convergence of multiple biosynthetic pathways that are widely distributed through the plant and animal kingdoms. Many of them have been discovered through bioassay-guided chemical investigations of traditional medicines, suggesting potential therapeutic significance. Their unique structures and varied pharmacological activities may provide important new leads for the discovery of drugs with novel mechanisms of action. Potential therapeutic indications are as diverse as cancer and viral infections, inflammation and immunomodulation, neurological and psychiatric conditions, and diabetes.

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Section: Resultsmentioning

confidence: 99%

Chromone and Flavonoid Alkaloids: Occurrence and Bioactivity

2011

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“…At the A‐ring of flavan‐3‐ols, C 6 and C 8 are reactive carbons that can react with electron accepting compounds and produce many kinds of C 6 or C 8 substituted catechins. A series of N ‐ethyl‐pyrrolidinone substituted flavan‐3‐ols (EPSFs) has been isolated and identified from black, postfermented (dark tea), white, and yellow teas (Dai et al., ; Tanaka, Watarumi, Fujieda, & Kouno, ; Wang et al., ; Zhou et al., ). It is hypothesized that the Strecker degradation product of theanine is involved in the formation of N ‐ethyl‐pyrrolidinone substituted flavan‐3‐ols.…”

Section: Tea Chemistrymentioning

confidence: 99%

Chemistry and Biological Activities of Processed Camellia sinensis Teas: A Comprehensive Review

Liang

Zhou

et al. 2019

Comp Rev Food Sci Food Safe

362

237

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Tea is a typical processed beverage from the fresh leaves of Camellia sinensis [Camellia sinensis (L.) O. Kuntze] or Camellia assamica [Camellia sinensis var. assamica (Mast.) Kitamura] through different manufacturing techniques. The secondary metabolites of fresh tea leaves are mainly flavan‐3‐ols, phenolic acids, purine alkaloids, condensed tannins, hydrolysable tannins, saponins, flavonols, and their glycoside forms. During the processing, tea leaves go through several steps, such as withering, rolling, fermentation, postfermentation, and roasting (drying) to produce different types of tea. After processing, theaflavins, thearubigins, and flavan‐3‐ols derivatives emerge as the newly formed compounds with a corresponding decrease in concentrations of catechins. Each type of tea has its own critical process and presents unique chemical composition and flavor. The components among different teas also cause significant changes in their biological activities both in vitro and in vivo. In the present review, the progress of tea chemistry and the effects of individual unit operation on components were comprehensively described. The health benefits of tea were also reviewed based on the human epidemiological and clinical studies. Although there have been multiple studies about the tea chemistry and biological activities, most of existing results are related to tea polyphenols, especially (‐)‐epigallocatechin gallate. Other compounds, including the novel compounds, as well as isomers of amino acids and catechins, have not been explored in depth.

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“…The few examples comprise davalliosides A and B from Davallia mariesii, 14) dracosephins A-D from Dracocephalum rupestre, 15) prolinalins A and B from Bombyx mori, 17) aquiledine and isoaquiledine from Aquilegia ecalcarata, 18) ficine and isoficine from Ficus pantoniana, 19) and ethylpyrrolididinonyl theasinensin A from commercial black tea. 20) In a previous work, Kouno group 20) obtained 6-(N-ethyl-2-pyrrolidinone-5-yl)-epicatechin-3-O-gallate by condensation between epicatechin-3-O-gallate and 1-ethyl-5-hydroxy-2-pyrrolidinone, which was spontaneously produced from the Strecker aldehyde of theanine, in acidic aqueous solution. 5-Hydroxypyrrolidin-2-one has been isolated from several higher plants including Jatropha curcas 21) and Pteridium aquillinum.…”

Section: Notesmentioning

confidence: 99%