title: Use of directly coupled ion-exchange liquid chromatography-mass spectrometry and liquid chromatography-nuclear magnetic resonance spectroscopy as a strategy for polar metabolite identification.
abstract: Ion-exchange LC-MS and LC-NMR have been successfully used to identify a novel N-acetyl metabolite of a highly polar drug candidate [2-(ethanimidoylamino)ethyl]sulfonyl alanine (GW273629) under development as a therapeutic agent. This has been achieved using a simple HPLC method without the need for complicated and time consuming pre- or post-column derivatisation. Ion-exchange chromatography using simple ionic strength buffer and organic solvent mobile phases, as applied here, should be suitable for the analysis of other charged polar species. Optimisation of the system described could result in the development of a rational generic HPLC approach specifically designed for the characterisation of polar drug molecules and their metabolites.
authors.affiliation: Bioanalysis and Drug Metabolism Division, GlaxoWellcome Research and Development, Ware, Herts, UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Dear
authors.forename: R S
authors.initials: RS
authors.lastname: Plumb
authors.forename: B C
authors.initials: BC
authors.lastname: Sweatman
authors.forename: P S
authors.initials: PS
authors.lastname: Parry
authors.forename: A D
authors.initials: AD
authors.lastname: Roberts
authors.forename: J C
authors.initials: JC
authors.lastname: Lindon
authors.forename: J K
authors.initials: JK
authors.lastname: Nicholson
authors.forename: I M
authors.initials: IM
authors.lastname: Ismail
mesh_terms: D000818:Animals; D002021:Buffers; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004791:Enzyme Inhibitors / Q000652:urine*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents; D013450:Sulfones / Q000652:urine*
chemical_list: D002021:Buffers; D004791:Enzyme Inhibitors; C409003:GW 273629; D012997:Solvents; D013450:Sulfones