title: Simultaneous enantiomer determination of 20 (R)- and 20 (S)-ginsenoside-Rg2 in rat plasma after intravenous administration using HPLC method.
abstract: 20 (R,S)-Ginsenoside-Rg2, an anti-shock agent, is prescribed as a racemate. To analyze simultaneously the enantiomers of 20 (R)-ginsenoside-Rg2 and 20 (S)-ginsenoside-Rg2 in plasma, a simple and reproducible high-performance liquid chromatographic (HPLC) method has been developed. The enantiomeric separation and determination were successfully achieved using a Diamonsil ODS C18 reversed-phase column (5 microm, 250 mm x 4.6 mm) with an RP18 (5 microm) guard column and a mobile phase of MeOH-aq. 4% H3PO4 (65:35, v/v, pH 5.1) with UV detection at 203 nm. Both enantiomers, 20 (R)-ginsenoside-Rg2 and 20 (S)-ginsenoside-Rg2, were well separated at 14.5 min and 13.6 min, respectively. The linear ranges of the standard curves were 2.0-250 microg/ml. The intra- and inter-day precision (R.S.D.) were <or=1.59% and <or=0.54% and the mean extraction recoveries were 95.8% and 96.5% for 20 (R)-ginsenoside-Rg2 and 20 (S)-ginsenoside-Rg2 in rat plasma, respectively. The limits of detection and quantification were 2.0 microg/ml and 7.8 microg/ml (S/N=3:1) for 20 (R)-ginsenoside-Rg2, and 2.0 microg/ml and 3.9 microg/ml (S/N=3:1) for 20 (S)-ginsenoside-Rg2, respectively. This validated method was applicable to pharmacokinetic studies in rat plasma after intravenous administration of 20 (R,S)-ginsenoside-Rg2. A pharmacokinetic study in rat plasma indicated that the enantiomers were rapidly absorbed and eliminated. These assay results are necessary for the evaluation of the metabolism of ginsenoside-Rg2 in vivo.
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, and Medical and Healthy Analysis Center, Peking University, Beijing 100083, China.
authors.forename: Fang-Jin
authors.initials: FJ
authors.lastname: Gui
authors.forename: Xiu-Wei
authors.initials: XW
authors.lastname: Yang
authors.forename: Long-Yun
authors.initials: LY
authors.lastname: Li
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Tian
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D036145:Ginsenosides / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D007275:Injections, Intravenous; D051381:Rats; D015203:Reproducibility of Results; D013237:Stereoisomerism
chemical_list: D036145:Ginsenosides; C026474:ginsenoside Rg2