title: Simultaneous determination of hypericin and hyperforin in human plasma with liquid chromatography-tandem mass spectrometry.
abstract: A selective and sensitive method for the simultaneous determination of hypericin and hyperforin--the two main active ingredients of St. John's Wort (SJW) extract--in human plasma depending on liquid/liquid-extraction and LC/MS/MS detection has been developed, validated after specifying the stability of the photosensitive hypericin in plasma samples during light exposure and applied to samples of a patient. After extraction with ethyl acetate/n-hexane in the darkness, sample extracts were chromatographed isocratically within 6 min on a Kromasil RP-18 column. The analytes were detected with tandem mass spectrometry in the selected reaction monitoring mode using an electrospray ion source. The limit of quantification was 0.05 ng/mL for hypericin and 0.035 ng/mL for hyperforin. The accuracy of the method varied between 101.9 and 114.2% and the precision ranged from 4.7 to 15.4% (S.D., batch-to-batch) for both analytes. The method was linear at least between 0.05 and 10 ng/mL for hypericin and between 0.035 and 100 ng/mL for hyperforin. Using this method hypericin and hyperforin were determined successfully in a patient over seven days following discontinuation of exposure with therapeutic doses of St. John's Wort extract.
authors.affiliation: Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany.
authors.forename: Klaus-Dieter
authors.initials: KD
authors.lastname: Riedel
authors.forename: Karin
authors.initials: K
authors.lastname: Rieger
authors.forename: Meret
authors.initials: M
authors.lastname: Martin-Facklam
authors.forename: Gerd
authors.initials: G
authors.lastname: Mikus
authors.forename: Walter E
authors.initials: WE
authors.lastname: Haefeli
authors.forename: Jürgen
authors.initials: J
authors.lastname: Burhenne
mesh_terms: D000368:Aged; D000873:Anthracenes; D001643:Bridged Bicyclo Compounds / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D010569:Perylene / Q000031:analogs & derivatives* / Q000097:blood*; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013729:Terpenes / Q000097:blood*
chemical_list: D000873:Anthracenes; D001643:Bridged Bicyclo Compounds; D013729:Terpenes; D010569:Perylene; C004965:hypericin; D010696:Phloroglucinol; C001654:hyperforin