Synthesis of Three Novel Fluorine-18 Labeled Analogues of <scp>l</scp>-Deprenyl for Positron Emission Tomography (PET) studies of Monoamine Oxidase B (MAO-B)
作者:Sangram Nag、Lutz Lehmann、Tobias Heinrich、Andrea Thiele、Georg Kettschau、Ryuji Nakao、Balázs Gulyás、Christer Halldin
DOI:10.1021/jm200710b
日期:2011.10.27
The aim in this project was to synthesize and to study fluorine-18 labeled analogues of L-deprenyl which bind selectively to the enzyme monoamine oxidase B (MAO-B). Three fluorinated L-deprenyl analogues have been generated in multistep organic syntheses. The most promising fluorine-18 compound N-[(2S)-1-[F-18]fluoro-3-phenylpropan-2-yl]-N-methylprop-2-yn-1-amine (4c) was synthesized by a one-step fluorine-18 nucleophilic substitution reaction. Autoradiography on human brain tissue sections demonstrated specific binding for compound 4c to brain regions known to have a high content of MAO-B. In addition, the corresponding nonradioactive fluorine-19 compound (13) inhibited recombinant human MAO-B with an IC50 of 170.5 +/- 29 n/v1 but did not inhibit recombinant human MAO-A (IC50 > 2000 nM), demonstrating its specificity. Biodistribution of 4c in mice showed high initial brain uptake leveling at 5.4 +/- 0.04%ID/g after 2 min post injection. In conclusion, compound 4c is a specific inhibitor of MAO-B with high initial brain uptake in mice and is, therefore, a candidate for further investigation in PET.