Synthesis, evaluation and metabolic studies of radiotracers containing a 4-(4-[18F]-fluorobenzyl)piperidin-1-yl moiety for the PET imaging of NR2B NMDA receptors
摘要:
In this study, novel specific PET radioligands containing the 4-(4-fluorobenzyl)piperidine moiety and selectively antagonistic for the NR2B subunit containing NMDA receptors were developed. Two antagonists, RGH-896 (1a) and 4-(4-fluorobenzyl)piperidinyl-1-methyl-2-benzimidazol-5-ol (2a), belonging to two different structural families, were radiolabeled by an aromatic nucleophilic radiofluorination followed by a reduction of the para-position carbonyl function. Radiotracers [F-18]1a, [F-18]2a or the pattern 4-(4-[(18)[F]-fluorobenzyl)piperidine ([(18)[F]6) demonstrated an identical in vivo behavior with high accumulation of radioactivity in bone and cartilage which would suggest a radiodefluorination of the radiotracers. The identification of metabolites from 6 by LC-MS-MS confirmed the significant degree of defluorination as a result of the in vivo hydroxylation in the benzyl ring. In conclusion, [(18)[F]1a or [(18)[F]2a are not suitable for imaging the NR2B NMDA receptors due to their poor brain penetration. We also argue for a cautious use of the radiolabeled pattern, 4-(4-[(18)[F]-fluorobenzyl)piperidine, to develop PET radiotracers.(C) 2011 Elsevier Masson SAS. All rights reserved.
[EN] 2-[(4-BENZYL)-1-PIPERIDINYL)METHYL]BENZIMIDAZOLE-5-OL DERIVATIVES AS NR2B RECEPTOR ANTAGONISTS<br/>[FR] UTILISATION DE DERIVES DE 2-[(4-BENZYL)-1-PIPERIDINYL)METHYL]BENZIMIDAZOLE-5-OL COMME ANTAGONISTES DES RECEPTEURS DU NR2B
申请人:MERCK & CO INC
公开号:WO2004048364A1
公开(公告)日:2004-06-10
2-[(4-Benzyl)-1-piperidinyl)-methyl]benzimidazole-5-ol derivatives are NMDA NR2B receptor antagonists useful in the treatment of pain and other NMDA mediated diseases.
2-[(4-Benzyl)-1-piperidinyl)methyl]benzimidazole-5-ol derivatives as nr2b receptor antagonists
申请人:McCauley A John
公开号:US20060160853A1
公开(公告)日:2006-07-20
2-[(4-Benzyl)-1-piperidinyl)-methyl]benzimidazole-5-ol derivatives are NMDA NR2B receptor antagonists useful in the treatment of pain and other NMDA mediated diseases.