Liquid chromatography–tandem mass spectrometry identification of metabolites of three phenylcarboxyl derivatives of the 5-HT1A antagonist, N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridyl) trans-4-fluorocyclohexanecarboxamide
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- 作者：Ma ; Ying ; Lang ; Lixin ; Kiesewetter ; Dale O. ; Eckelman ; William C.
- 关键词：FCWAY analogues ; 5-HT antagonists
- 刊名：Journal of Chromatography B, Analytical Technologies in the Biomedical and Life Sciences
- 出版年：2002
- 出版时间：November 15, 2002
- 年：2002
- 卷：780
- 期：1
- 页码：99-110
- 全文大小：1.07 M
文摘
We have previously described fluorine-18 radiolabeled FCWAY [N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridyl) trans-4-fluorocyclohexanecarboxamide] as a high affinity ligand for imaging the 5-HT1A receptor in vivo. In a search for radiopharmaceuticals with unique imaging applications using positron emission tomography (PET), we have also developed three new phenylcarboxamide analogues of FCWAY. Two of these analogues were generated by replacing the fluorocyclohexane carboxylic acid with fluorobenzoic acid (FBWAY) or with 3-methyl-4-fluorobenzoic acid (MeFBWAY). The final analogue was generated by replacing the pyridyl group with a pyrimidyl group and the fluorocyclohexane carboxylate with fluorobenzoic acid (FPWAY). We evaluated the metabolic profile of these compounds using either human or rat hepatocytes to produce metabolites and LC–MS/MS to identify these metabolites. We also compared the metabolic rate of these compounds in human or rat hepatocytes. These in vitro metabolism studies indicate that hydrolysis of the amide linkage was the major metabolic pathway for FPWAY and FBWAY in human hepatocytes, whereas aromatic oxidation is the major metabolic pathway for MeFBWAY. The comparative metabolic rate in human hepatocytes was FPWAY>FBWAY>MeFBWAY. In rat hepatocytes, aromatic oxidation was the major metabolic pathway for all three analogs and the rate of this process was similar for all of the analogues. These in vitro metabolic studies demonstrated species differences prior to the acquisition and interpretation of in vivo results.