Investigation of the in vitro metabolism of the emerging drug candidate S107 for doping-preventive purposes
Deutscher übersetzter Titel: | Untersuchung des In-vitro-Stoffwechsels des aufkommenden Pharmakon-Kandidaten S107 zu Doping-Präventionszwecken |
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Autor: | Beuck, Simon; Schänzer, Wilhelm; Thevis, Mario |
Erschienen in: | European journal of mass spectrometry |
Veröffentlicht: | 46 (2011), 2, S. 112-130, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Elektronische Ressource (online) Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 1469-0667, 1751-6838 |
DOI: | 10.1002/jms.1878 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU201410009676 |
Quelle: | BISp |
Abstract des Autors
The metabolic fate of the emerging drug candidate S107, possessing the potential for misuse as performance-enhancing agent in sports, was investigated by in vitro phase I and II experiments with human microsomal and S9 liver enzymes. The metabolites were identified by liquid chromatography-mass spectrometry with electrospray ionisation in positive mode (LC-ESI-MS/MS). Their collision-induced dissociation behaviour was studied by high-resolution/high accuracy Orbitrap MS(n) analysis, supported by stable isotope labelling, H/D-exchange experiments and density functional theory calculations. Monooxygenation accounted for the main phase I metabolic transformation due to N- and S-oxidation of the 1,4-benzothiazepine core, as substantiated by chemical synthesis, selective reduction methods and characteristic APCI in source fragmentation behaviour of the metabolites. Another dominant metabolic pathway was demethylation, yielding the N- and O-demethylated metabolite, respectively. The latter was further conjugated by glucuronidation as well as sulfonation in subsequent phase II metabolic reactions, whereas the N-demethylated metabolite was not amenable to conjugation. The active drug molecule itself was converted to two glucuronic acid conjugates, which are proposed to consist of two quaternary S107-N(+)-glucuronide isomers. All glucuronides were susceptible to enzymatic hydrolysis with β-glucuronidase (Escherichia coli). A comprehensive LC-ESI-MS(/MS)-based detection method for urine was developed and its fitness for purpose was assessed. The assay can serve as a potential screening and/or confirmation method for S107 in clinical drug testing and doping control analysis in the future. Verf.-Referat