N-2-(4-N-(4-[18F]Fluorobenzamido)phenyl)-propyl-2-propanesulphonamide: synthesis and radiofluorination of a putative AMPA receptor ligand
作者:Ute B. Kronenberg、Birte Drewes、Wiebke Sihver、Heinz H. Coenen
DOI:10.1002/jlcr.1413
日期:2007.11
Arylpropylsulphonamides are in the focus of research as α-amino-3-hydroxy-5-methyl-4-isoxazolpropionic acid (AMPA) receptor ligands. A new fluorine-18-labelled potentiator of AMPA receptors was synthesized as a potential radiotracer for cerebral imaging with positron emission tomography. Using N-2-(4-N-(4-nitrobenzamido)phenyl)-propyl-2-propanesulphonamide (7) as labelling precursor for a Kryptofix 2.2.2®/K2CO3-activated nucleophilic radiofluorination, the putative AMPA receptor ligand N-2-(4-N-(4-[18F]fluorobenzamido)phenyl)-propyl-2-propanesulphonamide [18F]8 was obtained in one step. Optimization of the reaction parameters time, temperature, solvent and concentration gave a radiochemical yield of 38±8% at 180°C in dimethylsulphoxide within 30-min reaction time. After a solid-phase extraction followed by a high-performance liquid chromatography separation, the product could be obtained in radiochemical yields of 5±1.5%. Radiochemical purity was higher than 95% and the specific activity amounted to 77±40 GBq/µmol. First in vitro assays with rat brain slices revealed a high non-specific binding and a uniform distribution of [18F]8 not lending it for in vivo imaging purposes. Copyright © 2007 John Wiley & Sons, Ltd.
作为α-氨基-3-羟基-5-甲基-4-异恶唑丙酸(AMPA)受体配体,芳基丙基磺酰胺类化合物是研究的重点。我们合成了一种新的氟-18 标记的 AMPA 受体增效剂,作为正电子发射断层扫描脑成像的潜在放射性示踪剂。使用 N-2-(4-N-(4-硝基苯甲酰胺基)苯基)-丙基-2-丙磺酰胺 (7) 作为 Kryptofix 2.2.2®/K2CO3 激活的亲核放射性氟化反应的标记前体,一步就得到了假定的 AMPA 受体配体 N-2-(4-N-(4-[18F]氟苯甲酰胺基)苯基)-丙基-2-丙磺酰胺 [18F]8。对反应时间、温度、溶剂和浓度等参数进行优化后,在二甲基亚砜中,温度为 180°C,反应时间为 30 分钟,放射化学收率为 38±8%。经过固相萃取和高效液相色谱分离后,产物的放射化学收率为 5±1.5%。放射化学纯度高于 95%,比活度为 77±40 GBq/µmol。用大鼠脑片进行的首次体外试验显示,[18F]8 的非特异性结合率很高,且分布均匀,不适合用于体内成像。Copyright © 2007 John Wiley & Sons, Ltd. All Rights Reserved.