title: High-performance liquid-chromatographic-atmospheric-pressure chemical-ionization ion-trap mass-spectrometric identification of isomeric C6-hydroxy and C20-hydroxy metabolites of methylprednisolone in the urine of patients receiving high-dose pulse therapy.
abstract: Fourteen metabolites of methylprednisolone have been analysed by gradient-elution high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). The compounds were separated on a Cp Spherisorb 5 microm ODS column connected to a guard column packed with pellicular reversed phase. The mobile phase was an acetonitrile- 1.0% aqueous acetic acid gradient at a flow rate of 1.5 mL min(-1) The analysis gave a complete picture of parent drug, prodrugs and metabolites, and the alpha/beta stereochemistry was resolved. The short (1-2 h) elimination half-life of methylprednisolone is explained by extensive metabolism. The overall picture of the metabolic pathways of methylprednisolone is apparently simple-reduction of the C20 carbonyl group and further oxidation of the C20,C21 side chain (into C21COOH and C20COOH), in competition with or in addition to oxidation at the C6 position.
authors.affiliation: Institute of Anaesthesiology, Academic Hospital Nijmegen Sint Radboud, The Netherlands.
authors.forename: T B
authors.initials: TB
authors.lastname: Vree
authors.forename: L
authors.initials: L
authors.lastname: Maljers
authors.forename: N
authors.initials: N
authors.lastname: Van den Borg
authors.forename: N M
authors.initials: NM
authors.lastname: Nibbering
authors.forename: C P
authors.initials: CP
authors.lastname: Verwey-van Wissen
authors.forename: A J
authors.initials: AJ
authors.lastname: Lagerwerf
authors.forename: R A
authors.initials: RA
authors.lastname: Maes
authors.forename: P J
authors.initials: PJ
authors.lastname: Jongen
mesh_terms: D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000378:metabolism* / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005965:Glucuronates / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008775:Methylprednisolone / Q000008:administration & dosage / Q000378:metabolism* / Q000652:urine; D008776:Methylprednisolone Hemisuccinate / Q000008:administration & dosage / Q000378:metabolism / Q000652:urine; D010084:Oxidation-Reduction; D011355:Prodrugs / Q000378:metabolism*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
chemical_list: D000893:Anti-Inflammatory Agents; D005965:Glucuronates; D011355:Prodrugs; D014867:Water; D008776:Methylprednisolone Hemisuccinate; C029110:methylprednisolone 17-hemisuccinate; D008775:Methylprednisolone