Pharmacokinetics of the new thyrotropin releasing hormone analogue montirelin hydrate. 3rd communication: identification of metabolites in rat urine
Sugimoto, T.; Hayashi, T.; Okita, A.; Morino, A.
Arzneimittel-Forschung 46(2): 127-133
1996
ISSN/ISBN: 0004-4172 PMID: 8720300 Document Number: 459932
The metabolism of montirelin hydrate (CAS 90243-66-6, NS-3) was studied in rats after intravenous administration of 14C-labeled or unlabeled NS-3. 1. Four radioactive metabolites (M-1 to M-4) were found in the urine after administration of 14C-NS-3. M-3 (major metabolite) and M-2 showed the same Rf values as (-)-N-[[(3R,6R)-6-methyl-5-oxo-3-thiomorpholinyl]carbonyl]-L-histi dyl-L- proline (CNK-6004) and (+)-N-[[(3R,6R)-6-methyl-5-oxo-3- thiomorpholinyl]carbonyl]-L-histidine (CNK-6001), respectively. 2. M-3 and M-2 were purified from the urine after administration of unlabeled NS-3, and their chemical structures were identified by mass spectrometry, 1H-nuclear magnetic resonance spectroscopy, thin-layer chromatography and high performance liquid chromatography. Consequently, M-3 was identified as CNK-6004 formed by deamidation at a prolinamide moiety of NS-3, and M-2 as CNK-6001 formed by deprolination of CNK-6004.