title: Quantitative measurement of sulforaphane, iberin and their mercapturic acid pathway metabolites in human plasma and urine using liquid chromatography-tandem electrospray ionisation mass spectrometry.
abstract: A quantitative liquid chromatography positive ion electrospray tandem mass spectrometric method for the simultaneous determination of sulforaphane, iberin and their metabolites in human urine and plasma is described. The stability of the metabolites was determined in aqueous solution and in human plasma. Gradient liquid chromatographic separation was performed on a Zorbax SB-Aq 3.5 microm (100 x 2.1mm) column, using a mobile phase (flow rate 0.25 mL/min) consisting of ammonium acetate buffer at pH 4 and acetonitrile. Butyl thiocarbamoyl l-cysteine was used as internal standard. The assay was linear (r(2)>0.99) over the range of 0.03-300 microM in urine and 0.03-15 microM in plasma with intra- and inter-day assay precision (<10% CV) and accuracy (<20%). The lower limits of quantitation were in the range of 10-150 nmol/L. The method has been used to report, for the first time, individual quantitative measurement of each of the mercapturic acid pathway metabolites of sulforaphane and iberin in both human plasma and urine following a dietary study of broccoli consumption.
authors.affiliation: Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Al Janobi
authors.forename: Richard F
authors.initials: RF
authors.lastname: Mithen
authors.forename: Amy V
authors.initials: AV
authors.lastname: Gasper
authors.forename: P Nicholas
authors.initials: PN
authors.lastname: Shaw
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Middleton
authors.forename: Catharine A
authors.initials: CA
authors.lastname: Ortori
authors.forename: David A
authors.initials: DA
authors.lastname: Barrett
mesh_terms: D000111:Acetylcysteine / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D017879:Isothiocyanates / Q000097:blood / Q000378:metabolism* / Q000652:urine; D015394:Molecular Structure; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013454:Sulfoxides; D013861:Thiocyanates / Q000097:blood / Q000378:metabolism* / Q000652:urine
chemical_list: D017879:Isothiocyanates; D013454:Sulfoxides; D013861:Thiocyanates; C082585:iberin; C016766:sulforaphane; D000111:Acetylcysteine