A high-yield automated radiosynthesis of the alpha-7 nicotinic receptor radioligand [18F]NS10743

Rodrigo Teodoro; Barbara Wenzel; Arata Oh-Nishi; Steffen Fischer; Dan Peters; Tetsuya Suhara; Winnie Deuther-Conrad; Peter Brust

doi:10.1016/j.apradiso.2014.09.016

A high-yield automated radiosynthesis of the alpha-7 nicotinic receptor radioligand [¹⁸F]NS10743

Appl Radiat Isot. 2015 Jan:95:76-84. doi: 10.1016/j.apradiso.2014.09.016. Epub 2014 Oct 8.

Authors

Rodrigo Teodoro¹, Barbara Wenzel², Arata Oh-Nishi³, Steffen Fischer², Dan Peters⁴, Tetsuya Suhara³, Winnie Deuther-Conrad², Peter Brust²

Affiliations

¹ Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany. Electronic address: r.teodoro@hzdr.de.
² Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany.
³ Molecular Neuroimaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan.
⁴ DanPET AB, Malmö, Sweden.

PMID: 25464181
DOI: 10.1016/j.apradiso.2014.09.016

Abstract

[¹⁸F]NS10743, a promising and highly competitive α7 nAChR radioligand has been synthesized so far by microwave irradiation using a manual single-mode device followed by a palladium-catalyzed reduction of remaining nitro-precursor for HPLC separation purposes. For further preclinical and clinical use, regulated production of [¹⁸F]NS10743 by fully automated radiosynthesis is a crucial requirement. Therefore, we chose a commercial synthesis module and developed the automated radiosynthesis of [¹⁸F]NS10743. Besides evaluation of several radiosynthesis procedures, we performed an extensive HPLC study for quantitative separation of [¹⁸F]NS10743 from the corresponding nitro precursor. After implementation of the optimized procedure on a TRACERlab^TM FX F-N synthesis module, [¹⁸F]NS10743 was obtained in high radiochemical purity (≥99%) with an overall radiochemical yield of 32.2±7% (n=3). The specific activities at the end of the synthesis were 571±17GBq/µmol (n=3).

Keywords: Alpha-7 nicotinic acetylcholine receptor radioligand; Automated radiosynthesis; Pet WAVE microwave CEM(®); Radiofluorination; TRACERlab(TM) FX F-N.