Synthesis of 6-[18F]fluoro-PBR28, a novel radiotracer for imaging the TSPO 18kDa with PET
作者:Annelaure Damont、Raphaël Boisgard、Bertrand Kuhnast、Frédéric Lemée、Guillaume Raggiri、Alana M. Scarf、Eleonora Da Pozzo、Silvia Selleri、Claudia Martini、Bertrand Tavitian、Michael Kassiou、Frédéric Dollé
DOI:10.1016/j.bmcl.2011.06.048
日期:2011.8
6-Fluoro-PBR28 (N-(6-fluoro-4-phenoxypyridin-3-yl)-N-(2-methoxybenzyl) acetamide), a fluorinated analogue of the recently developed TSPO 18 kDa ligand PBR28, was synthesized and labelled with fluorine- 18. 6-Fluoro-PBR28 and its 6-chloro/6-bromo counterparts were synthesized in six chemical steps and obtained in 16%, 10% and 19% overall yields, respectively. Labelling with fluorine-18 was performed in one single step (chlorine/bromine-for-fluorine heteroaromatic substitution) using a Zymate-XP robotic system affording HPLC-purified, ready-to-inject, 6-[F-18] fluoro-PBR28 (> 95% radiochemically pure). Non-decay-corrected overall yields were 9-10% and specific radioactivities ranged from 74 to 148 GBq/mu mol. In vitro binding experiments, dynamic mu PET studies performed in a rat model of acute neuroinflammation (unilaterally, AMPA-induced, striatum-lesioned rats) and ex vivo autoradiography on the same model demonstrated the potential of 6-[F-18] fluoro-PBR28 to image the TSPO 18 kDa using PET. (C) 2011 Elsevier Ltd. All rights reserved.