title: Mass spectrometric methods for the analysis of chlorinated and nitrated isoflavonoids: a novel class of biological metabolites.
abstract: Electrospray ionization combined with tandem mass spectrometry was applied to a study of some representative chlorinated and nitrated isoflavones-potential metabolites of isoflavones in inflammatory cells. Upon collision-induced dissociation of deprotonated [M - H](-) ions of these compounds, a number of structurally characteristic product ions were produced. The product ion analysis of 3'- and 8-chlorodaidzein in the tandom mass spectra led to ready differentiation of these isomers. 3-Nitro derivatives of both genistein and daidzein have product ions due to the losses of HNO(2) and two OH groups. Chlorinated derivatives of isoflavones were detected in cell-based experiments and their structures were proposed by comparing the tandem mass spectra of their product ions with those of standards. This work provides a suitable analytical basis to aid the characterization of chlorinated and nitrated metabolites in studies in vivo and in vitro.
authors.affiliation: Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: Jeevan K
authors.initials: JK
authors.lastname: Prasain
authors.forename: Rakesh
authors.initials: R
authors.lastname: Patel
authors.forename: Marion
authors.initials: M
authors.lastname: Kirk
authors.forename: Landon
authors.initials: L
authors.lastname: Wilson
authors.forename: Nigel
authors.initials: N
authors.lastname: Botting
authors.forename: Victor M
authors.initials: VM
authors.lastname: Darley-Usmar
authors.forename: Stephen
authors.initials: S
authors.lastname: Barnes
mesh_terms: D002713:Chlorine / Q000737:chemistry / Q000378:metabolism; D019833:Genistein / Q000032:analysis / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D007529:Isoflavones / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D007529:Isoflavones; D009566:Nitrates; C040641:genistin; D002713:Chlorine; C004742:daidzein; D019833:Genistein; C004541:biochanin A