title: Identification of benzo[c]phenanthridine metabolites in human hepatocytes by liquid chromatography with electrospray ion-trap and quadrupole time-of-flight mass spectrometry.
abstract: The metabolism of the benzo[c]phenanthridine alkaloids was studied using human hepatocytes which are an excellent model system for biotransformation studies. For analysis of the alkaloids and their metabolites, an electrospray quadrupole ion-trap mass spectrometry (ESI ion-trap MS) connected to a reversed phase chromatographic system based on cyanopropyl modified silica was used. The optimized experimental protocol allowed simultaneous analysis of the alkaloids and their metabolites and enabled study of their uptake into and interconversion in human hepatocytes. The results show that formation of the dihydro metabolite which may be followed by specific O-demethylenation/O-demethylation processes, is probably the main route of biotransformation (detoxification) of the benzo[c]phenanthridines in human hepatocytes. The structure of the main O-demethyl metabolite (2-methoxy-12-methyl-12,13-dihydro-[1,3]dioxolo[4',5':4,5]benzo[1,2-c]phenanthridin-1-ol; 336.1 m/z,) was proposed by the multi-stage MS and quadrupole time-of-flight MS methods using chemically synthesized standard.
authors.affiliation: Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Olomouc, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Kosina
authors.forename: Jan
authors.initials: J
authors.lastname: Vacek
authors.forename: Barbora
authors.initials: B
authors.lastname: Papoušková
authors.forename: Marie
authors.initials: M
authors.lastname: Stiborová
authors.forename: Jakub
authors.initials: J
authors.lastname: Stýskala
authors.forename: Petr
authors.initials: P
authors.lastname: Cankař
authors.forename: Eva
authors.initials: E
authors.lastname: Vrublová
authors.forename: Jitka
authors.initials: J
authors.lastname: Vostálová
authors.forename: Vilím
authors.initials: V
authors.lastname: Simánek
authors.forename: Jitka
authors.initials: J
authors.lastname: Ulrichová
mesh_terms: D000328:Adult; D000368:Aged; D053119:Benzophenanthridines / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics; D001711:Biotransformation; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D005260:Female; D022781:Hepatocytes / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007546:Isoquinolines / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D053119:Benzophenanthridines; D007546:Isoquinolines; C005705:sanguinarine; C016299:chelerythrine