title: Identification of palmatine and its metabolites in rat urine by liquid chromatography/tandem mass spectrometry.
abstract: Palmatine is an isoquinoline alkaloid that has been widely used in China for the treatment of various inflammatory diseases such as gynecological inflammation, bacillary dysentery, enteritis, respiratory tract infection, urinary infection, etc. In the study reported in this paper, a simple and rapid high-performance liquid chromatography/electrospray ionization (ESI) tandem mass spectrometric method (MS/MS) was developed for elucidation of the structures of metabolites of palmatine in rat urine after administration of a single dose (20 mg/kg). The rat urine samples were collected and purified through C18 solid-phase extraction cartridges, and then injected onto a reversed-phase C18 column with 60:40 (v/v) methanol/0.01% triethylamine solution (2 mM, adjusted to pH 3.5 with formic acid) as mobile phase and detected by on-line MS/MS. Identification of the metabolites and elucidation of their structures were performed by comparing changes in molecular masses (DeltaM), retention times and spectral patterns of product ions with those of the parent drug. As a result, six phase I metabolites, the parent drug palmatine and two phase II metabolites were identified in rat urine for the first time.
authors.affiliation: Bio-Technology of Traditional Chinese Medicine Key Laboratory of Hubei Province, Hubei University, Wuhan 430062, P.R. China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Zhu
authors.forename: Fengmei
authors.initials: F
authors.lastname: Han
authors.forename: Huaixia
authors.initials: H
authors.lastname: Chen
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Peng
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D001600:Berberine Alkaloids / Q000032:analysis / Q000737:chemistry / Q000378:metabolism* / Q000652:urine*; D002853:Chromatography, Liquid / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D015394:Molecular Structure; D051381:Rats; D017208:Rats, Wistar; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors
chemical_list: D001600:Berberine Alkaloids; C005413:palmatine