Synthesis and in vitro autoradiographic evaluation of a novel high-affinity radioiodinated ligand for imaging brain cannabinoid subtype-1 receptors
摘要:
There is strong interest to study the involvement of brain cannabinoid subtype-1 (CB1) receptors in neuropsychiatric disorders with single photon emission computed tomography ( SPECT) and a suitable radioligand. Here we report the synthesis of a novel high-affinity radioiodinated CB1 receptor ligand ([I-125]8, [I-125]1-(2-iodophenyl)-4-cyano-5-(4-methoxyphenyl)-N-(piperidin-1-yl)-1H-pyrazole-3-carboxylate, [I-125] SD7015). By autoradiography in vitro, [I-125]8 showed selective binding to CB1 receptors on human brain postmortem cryosections and now merits labeling with iodine-123 for further evaluation as a SPECT radioligand in non-human primate. (c) 2009 Elsevier Ltd. All rights reserved.
[EN] RADIOTRACERS FOR IMAGING CANNABINOID SUB-TYPE1 (CB1) RECEPTOR<br/>[FR] TRACEURS RADIOACTIFS POUR L'IMAGERIE DES RÉCEPTEURS CANNABINOÏDES DE SOUS-TYPE 1 (CB1)
申请人:US GOV HEALTH & HUMAN SERV
公开号:WO2009140210A2
公开(公告)日:2009-11-19
Imaging of cannabinoid subtype-1 (CB1) receptors in vivo is important for understanding their role in neuropsychiatric disorders and for drug development. Radioligands for imaging with PET or SPECT are required for this purpose. The present invention provides new ligands, including (-)-3-(4-chlorophenyl)-N'-[(4-cyanophenyl)sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamidine) and 1-(2-iodophenyl)-4-cyano-5-(4-methoxyphenyl)-N-(piperidin-1-yl)-1H-pyrazole-3-carboxylate, which were found to have high affinity and selectivity for binding to CB1 receptors. These compounds were labeled and evaluated as a PET and SPECT radioligands for use in mammals. After injection of [11C] (-)-3-(4-chlorophenyl)-N'-[(4-cyanophenyl)sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamidine) into mammals, high uptake and retention of radioactivity across brain according to the rank order of CB1 receptor densities was observed. Likewise 125I-labeled 1-(2-iodophenyl)-4-cyano-5-(4-methoxyphenyl)-N-(piperidin-1-yl)-1H-pyrazole-3-carboxylate showed a distinct regional distribution of radioactivity in brain tissue according to the known CB1 receptor densities. Ligands of the present invention are useful for in vivo imaging CB1 receptor function in mammals.
Synthesis and in vitro autoradiographic evaluation of a novel high-affinity radioiodinated ligand for imaging brain cannabinoid subtype-1 receptors
作者:Sean R. Donohue、Katarina Varnäs、Zhisheng Jia、Balázs Gulyás、Victor W. Pike、Christer Halldin
DOI:10.1016/j.bmcl.2009.08.092
日期:2009.11
There is strong interest to study the involvement of brain cannabinoid subtype-1 (CB1) receptors in neuropsychiatric disorders with single photon emission computed tomography ( SPECT) and a suitable radioligand. Here we report the synthesis of a novel high-affinity radioiodinated CB1 receptor ligand ([I-125]8, [I-125]1-(2-iodophenyl)-4-cyano-5-(4-methoxyphenyl)-N-(piperidin-1-yl)-1H-pyrazole-3-carboxylate, [I-125] SD7015). By autoradiography in vitro, [I-125]8 showed selective binding to CB1 receptors on human brain postmortem cryosections and now merits labeling with iodine-123 for further evaluation as a SPECT radioligand in non-human primate. (c) 2009 Elsevier Ltd. All rights reserved.