title: Simultaneous analysis of 2-methoxyphenylmetyrapone and its seven potential metabolites by high-performance liquid chromatography.
abstract: A sensitive and specific high-performance liquid chromatographic (HPLC) assay has been developed for the quantification of 2-methoxyphenylmetyrapone (2-MPMP) and its seven potential metabolites in rat urine and whole blood. 2-MPMP, 2-hydroxyphenylmetyrapone and their N-oxides, together with 2-methoxyphenylmetyrapol, 2-hydroxyphenylmetyrapol and their N-oxides were separated on an Isco Spherisorb ODS-2 reversed-phase column (250 x 4.6 mm, I.D., 5 microm), with an Isco Spherisorb ODS-2 guard cartridge (10 x 4.6 mm I.D.). A gradient elution was employed using solvent system A (acetonitrile-water-triethylamine-acetic acid, 27.3:69.1:0.9:2.7%, v/v) and solvent system B (methanol), the gradient program being as follows: initial 0-4 min A:B=74:26; 4-10 min linear change to A:B=50:50; 10-16 min maintain A:B=50:50; 16 min return to initial conditions (A:B=74:26). Flow-rate was maintained at 1.25 ml/min, and the eluent monitored using a diode array multiple wavelength UV detector set at 260 nm. Most of the analytes were baseline resolved, and analysis of samples recovered from blood or urine (pH 12, 3 x 5 ml of dichloromethane, recovery approximately 20-95%) revealed no interference from any co-extracted endogenous compounds in the biological matrices, except for 2-hydroxyphenylmetyrapol N-oxide (2-OHPMPOL-NO) at low concentrations. The calibrations (n=6) were linear (r > or = 0.996) for all analytes (approximately 0.5-100 microg/ml), with acceptable inter- and intra-day variability. Subsequent validation of the assay revealed acceptable precision, as measured by coefficient of variation (C.V.) at the low (0.5 mg/ml), medium (50 microg/ml) and high (100 microg/ml) concentrations. The limits of detection for 2-MPMP and their available potential metabolites, except 2-OHPMPOL-NO, in rat urine and blood were both 0.5 microg/ml, respectively.
authors.affiliation: Department of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories.
authors.forename: L A
authors.initials: LA
authors.lastname: Damani
authors.forename: M C
authors.initials: MC
authors.lastname: Tsai
authors.forename: G
authors.initials: G
authors.lastname: Lin
authors.forename: M
authors.initials: M
authors.lastname: Mitterhauser
authors.forename: I
authors.initials: I
authors.lastname: Zolle
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008297:Male; D008797:Metyrapone / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism / Q000652:urine; D008832:Microchemistry; D011786:Quality Control; D011849:Radioactive Tracers; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D012997:Solvents
chemical_list: C102846:2-methoxyphenylmetyrapone; D011849:Radioactive Tracers; D012997:Solvents; D008797:Metyrapone