Radiolabeling of a high potency cannabinoid subtype-1 receptor ligand, N-(4-fluoro-benzyl)-4-(3-(piperidin-1-yl)-indole-1-sulfonyl)benzamide (PipISB), with carbon-11 or fluorine-18
Radiolabeling of a high potency cannabinoid subtype-1 receptor ligand, N-(4-fluoro-benzyl)-4-(3-(piperidin-1-yl)-indole-1-sulfonyl)benzamide (PipISB), with carbon-11 or fluorine-18
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DOI:
10.1002/jlcr.1491
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发表时间:
2008-03-15
影响因子:
1.8
通讯作者:
Pike, Victor W.
中科院分区:
文献类型:
--
作者:
Donohue, Sean R.;Halldin, Christer;Pike, Victor W.
PipISB [N-(4-fluoro-benzyl)-4-(3-(piperidin-1-yl)-indole-1-sulfonyl)benzamide, 9] was identified as a selective high potency CB, receptor ligand. Here we describe the labeling of 9 with positron-emitters to provide candidate radioligands for imaging brain CB1 receptors with positron emission tomography (PET). The radiolabeling of 9 was achieved by two methods, method A with carbon-11 and method B with fluorine-18. In method A, [C-11]9 was prepared in one step from [C-11]carbon monoxide, itself prepared from cyclotron-produced [C-11]carbon dioxide. In method B, [F-18]9 was prepared from cyclotron-produced [F-18]fluoride ion in a two-stage, four-step synthesis with [18F]4-fluoro-benzyl bromide as a labeling agent. The radiosynthesis time for method A was 44 min; decay-corrected radiochemical yields (RCYs) from [C-11]carbon monoxide ranged from 3.1 to 11.6% and specific radioactivities ranged from 21 to 67 GBq/mu mol. The radiosynthesis time for method B was 115 min; RCYs from [F-18]fluoride ion ranged from 1.5 to 5.6% and specific radioactivities ranged from 200 to 348 GBq/mu mol. With these methods, [C-11]9 and [F-18]9 may be prepared in adequate activity and quality for future evaluation as PET radioligands.