title: A new LC/MS/MS rapid and sensitive method for the determination of green tea catechins and their metabolites in biological samples.
abstract: A new rapid and sensitive method has been developed, using liquid chromatography in tandem mass spectrometry (LC-ESI-MS/MS) to identify green tea catechin metabolites in plasma and urine after oral intake of a green tea extract. (-)-Epigallocatechin-3-gallate (EGCG), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC)-glucuronide, (-)-epicatechin (EC)-glucuronide, and EC-sulfate were identified in plasma, whereas in urine only the conjugated catechins were detected (EGC-glucuronide, EGC-sulfate, EC-glucuronide, and EC-sulfate). Standard calibration curves prepared in plasma were found to be linear in the range of 10.9-1379.3 nmol/L for EGCG, EGC, ECG, and EC. The accuracy and precision of this assay showed a coefficient of variation of <15%. The method allowed the detection and quantification limits (for 20 microL injection) from 1.1 to 2.6 nmol/L and 3.8-8.7 nmol/L, respectively, in plasma and 0.8-1.8 nmol/L and 2.6-6.0 nmol/L, respectively, in urine. This method can be applied for future clinical and epidemiological studies, allowing the identification of the active metabolites that will reach the target tissues.
authors: Department of Nutrition and Food Science, XARTA, Faculty of Pharmacy, University of Barcelona, Av. Joan XXIII s/n, 08028, Barcelona, Spain.
authors: Maria de Lourdes
authors: Mde L
authors: Mata-Bilbao
authors: Cristina
authors: C
authors: Andrés-Lacueva
authors: Elena
authors: E
authors: Roura
authors: Olga
authors: O
authors: Jáuregui
authors: Celina
authors: C
authors: Torre
authors: Rosa Maria
authors: RM
authors: Lamuela-Raventós
mesh_terms: D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002853:Chromatography, Liquid / Q000379:methods*; D004285:Dogs; D020719:Glucuronides / Q000097:blood / Q000652:urine; D013058:Mass Spectrometry / Q000379:methods*; D013662:Tea / Q000737:chemistry*
chemical_list: D020719:Glucuronides; D013662:Tea; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate