title: Identification of BVT.2938 metabolites by LC/MS and LC/MS/MS after in vitro incubations with liver microsomes and hepatocytes.
abstract: The metabolism of the 5HT2c agonist BVT.2938, 1-(3-[2-[(2-ethoxy-3-pyridinyl)oxy]ethoxy]-2-pyrazinyl)-2(R)-methylpiperazine, was studied in vitro by incubation with rat, monkey and human liver microsomes as well as cryopreserved hepatocytes, followed by liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS analysis on a quadrupole-time of flight mass spectrometer for structural elucidation. Deuterium exchange on column was used to differentiate between hydroxylation and N-oxidation. Liver microsomes were incubated in two different buffer systems with optimum conditions for cytochrome P450 activity or UDP-glucuronosyltransferase activity. The major phase I metabolites of BVT.2938 originated from O-deethylation of the pyridine ring, O-dealkylation of the ethylene bridge, pyrazine ring hydroxylation, hydroxylation of pyridine ring and piperazine ring N-hydroxylation. When a hydrogen carbonate buffer system was supplemented with UDPGA, the piperazine carbamoyl-glucuronide from the parent compound was identified together with several glucuronides of the phase I metabolites. The metabolite pattern in hepatocytes was similar to microsomes except that the sulphate at the N-position of the piperazine ring of BVT.2938 was identified, while the carbamoyl-glucuronide was missing. Excellent correlation was obtained between radioactivity detection and the chemiluminescent nitrogen detector when the nitrogen content of the analytes was taken into account.
authors.affiliation: Preclinical R&D, Biovitrum AB, Lindhagensgatan 133, SE-112 76 Stockholm, Sweden. per-olof.edlund@biovitrum.com
authors.forename: Per Olof
authors.initials: PO
authors.lastname: Edlund
authors.forename: Pawel
authors.initials: P
authors.lastname: Baranczewski
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D022781:Hepatocytes / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008252:Macaca fascicularis; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008862:Microsomes, Liver / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017366:Serotonin Receptor Agonists / Q000032:analysis* / Q000378:metabolism*
chemical_list: D017366:Serotonin Receptor Agonists