Syntheses and binding affinities of 6-nitroquipazine analogues for serotonin transporter: Part 3. A potential 5-HT transporter imaging agent, 3-(3-[18F]Fluoropropyl)-6-nitroquipazine

Abstract

3-(3-[F-18]Fluoropropyl)-6-nitroquipazine ([F-18]FPNQ) as a 5-HT transporter imaging agents was designed, synthesized, and evaluated. FPNQ was selected due to its potent in vitro biological activity (K-i = 0.32 nM) in rat brain cortical membranes. The F-18-labeled FPNQ was prepared by reaction of the propyl mesylate as a precursor with tetra-n-butylammonium [F-18]fluoride generated under NCA conditions. The precursor mesylate was synthesized from commercially available hydrocarbostyril in nine steps in 21% overall yield. The specific activity of the [F-18]FPNQ determined by radioreceptor assay was 27.0 GBq/mumol. Tissue distribution studies in mice showed the highest uptake in the frontal cortex (5.79 %ID/g) at 60 min post-injection. (C) 2003 Elsevier Ltd. All rights reserved.