title: Metabolism of Genipin in Rat and Identification of Metabolites by Using Ultraperformance Liquid Chromatography/Quadrupole Time-of-Flight Tandem Mass Spectrometry.
abstract: The in vivo and in vitro metabolism of genipin was systematically investigated in the present study. Urine, plasma, feces, and bile were collected from rats after oral administration of genipin at a dose of 50 mg/kg body weight. A rapid and sensitive method using ultraperformance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF MS) was developed for analysis of metabolic profile of genipin in rat biological samples (urine, plasma, feces, and bile). A total of ten metabolites were detected and identified by comparing their fragmentation patterns with that of genipin using MetaboLynx software tools. On the basis of the chromatographic peak area, the sulfated and glucuronidated conjugates of genipin were identified as major metabolites. And the existence of major metabolites G1 and G2 was confirmed by the in vitro enzymatic study further. Then, metabolite G1 was isolated from rat bile by semipreparative HPLC. Its structure was unambiguously identified as genipin-1-o-glucuronic acid by comparison of its UV, IR, ESI-MS, (1)H-NMR, and (13)C-NMR spectra with conference. In general, genipin was a very active compound that would transform immediately, and the parent form of genipin could not be observed in rats biological samples. The biotransformation pathways of genipin involved demethylated, ring-opened, cysteine-conjugated, hydroformylated, glucuronidated, and sulfated transformations.
authors.affiliation: Experiment Center for Teaching and Learning, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China ; School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ding
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Hou
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Zhang
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Cai
authors.forename: Li
authors.initials: L
authors.lastname: Yang