A new class of vesicular acetylcholine transporter inhibitor that incorporates a carbonyl group into the benzovesamicol structure was synthesized, and analogues were evaluated in vitro. (±)-trans-2-Hydroxy-3- (4-(4-[ 18F]fluorobenzoyl)piperidino)tetralin (9e) has K i values of 2.70 nM for VAChT, 191 nM for σ 1 and 251 nM for σ 2. The racemic precursor (9d) was resolved via chiral HPLC, and (±)-[ 18F]9e,(-)-[ 18F]9e, and (+)-[ 18F]9e were respectively radiolabeled via microwave irradiation of the appropriate precursors with [ 18F]/F- and Kryptofix/K 2CO 3 in DMSO with radiochemical yields of ∼50-60% and specific activities of >2000 mCi/μmol. (-)-[ 18F]9e uptake in rat brain was consistent with in vivo selectivity for the VAChT with an initial uptake of 0.911 %ID/g in rat striatum and a striatum/cerebellum ratio of 1.88 at 30 min postinjection (p.i.). MicroPET imaging of macaques demonstrated a 2.1 ratio of (-)-[ 18F]9e in putamen versus cerebellum at 2 h p.i. (-)-[ 18F]9e has potential to be a PET tracer for clinical imaging of the VAChT.
|Number of pages||12|
|Journal||Journal of Medicinal Chemistry|
|State||Published - Mar 12 2009|