title: Development of LC-MS/MS analysis of cyclic dipeptides and its application to tea extract.
abstract: 2,5-Diketopiperazines (DKPs), also called cyclic dipeptides, have been known to occur in various foods. Recently, DKPs have attracted attentions as bioactive components. There were some reports on analytical methods for DKPs, but the number of analyzed DKPs was only a part of all DKPs and the quantitative performance was not studied in detail. In this study, we selected 31 kinds of DKPs and developed a quantitative and simultaneous analytical method using LC-MS/MS. This method was applied to DKPs determination in Pu-erh tea, post-fermentation tea, and 18 kinds of DKPs were determined at concentration of 0.0017-0.11 ppm. As a result of spiked test, it was concluded that the developed method using LC-MS/MS was useful for estimating DKPs concentration in tea.
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.|b Innovation Development Department , Suntory Global Innovation Center Ltd. , Osaka , Japan.
authors: Kenji
authors: K
authors: Yamamoto
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.
authors: Miki
authors: M
authors: Hayashi
authors: c Quality Assurance Division , Suntory Business Expert Ltd. , Osaka , Japan.
authors: Yuka
authors: Y
authors: Murakami
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.
authors: Yoko
authors: Y
authors: Araki
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.
authors: Yuuki
authors: Y
authors: Otsuka
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.
authors: Takehiro
authors: T
authors: Kashiwagi
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.
authors: Tomoko
authors: T
authors: Shimamura
authors: a Faculty of Agriculture , Kochi University , Nankoku , Japan.
authors: Hiroyuki
authors: H
authors: Ukeda
mesh_terms: D002138:Calibration; D028241:Camellia sinensis / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D054659:Diketopiperazines / Q000737:chemistry / Q000302:isolation & purification*; D004151:Dipeptides / Q000737:chemistry / Q000302:isolation & purification*; D005285:Fermentation; D006801:Humans; D057230:Limit of Detection; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D054659:Diketopiperazines; D004151:Dipeptides; D010456:Peptides, Cyclic; D010936:Plant Extracts
keywords: 2,5-diketopiperazines; DKPs; LC-MS/MS; Pu-erh tea; cyclic dipeptide