title: High performance liquid chromatographic-mass spectrometric determination of ginsenoside Rg3 and its metabolites in rat plasma using solid-phase extraction for pharmacokinetic studies.
abstract: To support pharmacokinetic studies of ginsenosides, a novel method to quantitatively analyze ginsenoside Rg3 (Rg3), its prosapogenin ginsenoside Rh2 (Rh2) and aglycone 20(S)-protopanaxadiol (ppd) in rat plasma was developed and validated. The method was based on gradient separation of ginsenosides present in rat plasma using high performance liquid chromatography (HPLC), followed by detection with electrospray ionization(ESI) mass spectrometry (MS) in negative ion mode with the mobile phase additive, ammonium chloride (500 microM). Differentiation of ginsenosides was achieved through simultaneous detection of the [M(+)Cl(-)] adduct of ginsenoside Rg3 and [M(+)Cl(-)] adducts of its deglycosylated metabolites Rh2 and ppd, and other ions after solid phase extraction (SPE). The /specific ions monitored were m/z 819.50 for Rg3, m/z 657.35 for Rh2, m/z 495.40 for ppd and m/z 799.55 for the internal standard (digitoxin). The mean recoveries for Rg3, Rh2 and ppd were 77.85, 82.65 and 98.33%, respectively using 0.1 ml plasma for extraction. The lower limits of quantification were 10.0, 2.0 and 8.0 ng/ml (equivalent to 0.1, 0.02 and 0.08 ng in each 10 microl injection onto the HPLC column) for Rg3, Rh2 and ppd, respectively. The method has been demonstrated to be highly sensitive and accurate for the determination of Rg3 and its metabolites in rat plasma.
authors.affiliation: Key laboratory of Drug Metabolism and Pharmacokinetics, 24 Tong Jia Xiang Street, Mail Box 210, China Pharmaceutical University, Nanjing 210009, Jiangsu Province, China.
authors.forename: Hai-Tang
authors.initials: HT
authors.lastname: Xie
authors.forename: Guang-Ji
authors.initials: GJ
authors.lastname: Wang
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Sun
authors.forename: Ian
authors.initials: I
authors.lastname: Tucker
authors.forename: Xiao-Chen
authors.initials: XC
authors.lastname: Zhao
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Xie
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Xi-Ling
authors.initials: XL
authors.lastname: Jiang
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Mei-Juang
authors.initials: MJ
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D005615:Freezing; D036145:Ginsenosides / Q000097:blood* / Q000302:isolation & purification / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012502:Sapogenins / Q000097:blood / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization; D014315:Triterpenes / Q000097:blood / Q000302:isolation & purification
chemical_list: D036145:Ginsenosides; D012502:Sapogenins; D014315:Triterpenes; C097367:ginsenoside Rg3; C055305:ginsenoside Rh2; C062916:protopanaxadiol