title: Sensitive and selective liquid chromatography-electrospray ionisation-mass spectrometry analysis of astragaloside-IV in rat plasma.
abstract: Astragaloside-IV (3-O-beta-d-xylopyranosyl-6-O-beta-d-glucopyranosyl-cycloastragenol) is the major active constituent contained in Radix Astragali. This paper describes a rapid, sensitive and specific assay for quantitative determination of astragaloside-IV in rat plasma. After a liquid/liquid extraction (LLE) with n-butanol and high-performance liquid chromatography (HPLC) gradient separation with acetonitrile-NH4Cl solution (0.5 micromol/L) as the mobile phase, the anions adduct [M + Cl]- at m/z 819.4 of astragaloside-IV, and [M + Cl]- at m/z 815.35 of internal standard (IS) digoxin were analyzed by electrospray ionisation-mass spectrometry (LC-ESI-MS) in selected ion monitoring (SIM) mode. Chromatographic separation was achieved in less than 9 min and calibration curve was linear over a concentration range of 2-200 ng/ml. The described assay method was successfully applied to the preclinical pharmacokinetic study of astragaloside-IV. After intragastric administration of astragaloside-IV to rats, Cmax and Tmax of astragaloside-IV were 134.73 +/- 39.86 ng/ml and 1.5 h, respectively, and the elimination half-life (t1/2) was 5.45 +/- 0.39 h.
authors.affiliation: Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Chenrong
authors.initials: C
authors.lastname: Huang
authors.forename: Guangji
authors.initials: G
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Haitang
authors.initials: H
authors.lastname: Xie
authors.forename: Jianguo
authors.initials: J
authors.lastname: Sun
authors.forename: Hua
authors.initials: H
authors.lastname: Lv
authors.forename: Tian
authors.initials: T
authors.lastname: Lv
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D011786:Quality Control; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D015203:Reproducibility of Results; D012503:Saponins / Q000097:blood* / Q000493:pharmacokinetics; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization; D014315:Triterpenes / Q000097:blood* / Q000493:pharmacokinetics
chemical_list: D007202:Indicators and Reagents; D012503:Saponins; D012996:Solutions; D014315:Triterpenes; C052064:astragaloside A