title: [Quantitative investigation of glucuronidated icaritin metabolite in rats].
abstract: OBJECTIVE
  To establish an ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) method for the simultaneous quantification of icairitin(ICT) and its major metabolite glucuronidated icaritin (GICT), and investigate metabolism of ICT in rats following a single intraperitoneal administration.
  
  
  METHODS
  ICT, GICT and an internal standard coumestrol (CMT) were extracted from rat plasma using acetonitrile and separated on a C18 column using a gradient mobile phase of acetonitrile, water, ammonium formate and formic acid. In the negative electrospray ionization mode, selected reaction monitoring of the precursor-product ion transitions of m/z 367.1 --> 297.1 for ICT, 543.3 --> 367.1 for GICT and 267.0 - 211.1 for CMT was used for the quantification. Plasma was collected for the determination of ICT and GICT after rats were intraperitoneally administered with ICT at a single dose of 10 mg/kg.
  
  
  RESULTS
  The calibration curves were linear over the concentration range of 0.2 - 20 ng/ml for ICT and 2 -200 ng/ml for GICT with the respective lower limit of quantification at 0.2 and 2 ng/ml. The intra- and inter-day accuracy values fell in the range of 95.1 - 103.7%, and precisions were within 10.3%. Recovery and matrix effect were 89.1 - 92.4% and 93.2 - 104.2%, respectively.
  
  
  CONCLUSIONS
  The UHPLC-MS/MS method was specific and accurate, suitable for the metabolism study of ICT. ICT was rapidly metabolized to GICT in rats.
authors.forename: Shuangqing
authors.initials: S
authors.lastname: Zhang
authors.forename: Licui
authors.initials: L
authors.lastname: Sun
authors.forename: Zhenwu
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002853:Chromatography, Liquid; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000008:administration & dosage / Q000097:blood* / Q000302:isolation & purification / Q000493:pharmacokinetics*; D007274:Injections, Intraperitoneal; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D005419:Flavonoids; C499403:icaritin