title: Liquid chromatography with tandem mass spectrometry for the simultaneous determination of baicalein, baicalin, oroxylin A and wogonin in rat plasma.
abstract: A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of baicalein, baicalin, oroxylin A and wogonin, Scutellaria baicalensis active components in rat plasma was developed. After liquid-liquid extraction with 2-(3,4-dimethoxy-phenyl)-5,7-dihydroxy-chromen-4-one as internal standard, baicalein, baicalin, oroxylin A and wogonin were eluted from an Atlantis C(18) column within 7 min with isocratic mobile phase consisting of methanol and 0.1% formic acid (60:40, v/v). The analytes were detected using an electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode. The standard curves were linear (r=1.000) over the concentration ranges of 5-500 ng/ml for baicalein, wogonin and oroxylin A and 5-5000 ng/ml for baicalin. The coefficients of variation and relative errors of baicalein, wogonin, oroxylin A and baicalin for intra- and inter-assay at three or four quality control (QC) levels were 0.8-6.1% and -4.0 to 5.8%, respectively. The lower limits of quantification for baicalein, wogonin, oroxylin A and baicalin were 5ng/ml using 50 microl of plasma sample. This method was successfully applied to the pharmacokinetic study of baicalein, baicalin, wogonin and oroxylin A after an intravenous administration of Scutellariae radix extract to male Sprague-Dawley rats.
authors.affiliation: Drug Metabolism & Bioanalysis Lab., College of Pharmacy and Medicinal Resources Research Institute, Wonkwang University, Shinyongdong, Iksan 570-749, Republic of Korea.
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Jeong
authors.forename: In Bok
authors.initials: IB
authors.lastname: Paek
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Ji
authors.forename: Youn-Chul
authors.initials: YC
authors.lastname: Kim
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Sohn
authors.forename: Hye Suk
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D044950:Flavanones / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D005419:Flavonoids / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D008297:Male; D010936:Plant Extracts / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D031363:Scutellaria / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D044950:Flavanones; D005419:Flavonoids; D010936:Plant Extracts; C038044:baicalin; C006680:baicalein; C080669:5,7-dihydroxy-6-methoxy-2-phenylchromen-4-one; C085514:wogonin