title: In vivo metabolism study of rhubarb decoction in rat using high-performance liquid chromatography with UV photodiode-array and mass-spectrometric detection: a strategy for systematic analysis of metabolites from traditional Chinese medicines in biological samples.
abstract: High-performance liquid chromatography with diode-array detection (HPLC-DAD) and tandem mass spectrometry (HPLC-MS/MS) was used for separation and identification of metabolites in rat urine, bile and plasma after oral administration of rhubarb decoction. Based on the proposed strategy, 91 of the 113 potential metabolites were tentatively identified or characterized. Besides anthraquinones metabolites, gallic acid, (-)-epicatechin and (+)-catechin metabolites were also detected and characterized in these biological samples. Our results indicated that glucuronidation and sulfation were the main metabolic pathways of anthraquinones, while methylation, glucuronidation and sulfation were the main metabolic pathways of gallic acid, (-)-epicatechin and (+)-catechin. Phase I reactions (e.g., hydroxylation and reduction) played a relatively minor role compared to phase II reactions in metabolism of phenolic compounds of rhubarb decoction. The identification and structure elucidation of these metabolites provided essential data for further pharmacological and clinical studies of rhubarb and related preparations. Moreover, the results of the present investigations clearly indicated the relevance and usefulness of the combination of chromatographic, spectrophotometric, and mass-spectrometric analysis to detect and identify metabolites.
authors.affiliation: Department of Pharmaceutical Analysis, China Pharmaceutical University, Tongjia Lane 24, Nanjing 210009, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Song
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.forename: Fengguo
authors.initials: F
authors.lastname: Xu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.forename: Haijuan
authors.initials: H
authors.lastname: Dong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: Zunjian
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000880:Anthraquinones / Q000097:blood / Q000378:metabolism / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000378:metabolism*; D005419:Flavonoids / Q000097:blood / Q000378:metabolism / Q000652:urine; D005707:Gallic Acid / Q000097:blood / Q000378:metabolism / Q000652:urine; D008297:Male; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000097:blood / Q000378:metabolism* / Q000652:urine; D051381:Rats; D017207:Rats, Sprague-Dawley; D012250:Rheum / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014556:Urine / Q000737:chemistry*
chemical_list: D000880:Anthraquinones; D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D010936:Plant Extracts; D005707:Gallic Acid