Synthesis of [¹⁸F]fluoroethoxy‐benzovesamicol, a radiotracer for cholinergic neurons

Abstract

SUMMARYmapping agent for use in positron emission tomography (PET). This radiotracer was made by nucleophilic radiofluorination of tosyloxyethoxy-benzovesamicol, followed by reverse phase HPLC purification, in decay corrected radiochemical yield exceeding 60%.

Development of 18F-labeled radiotracers for neuroreceptor imaging with positron emission tomography

“…Similar affinity and selectivity have been found for (-)-FEOBV [125] , a radioligand first described in 1993 [126] and recently chosen for human VAChT studies [127] . Autoradiographic investigations of the human brain have revealed that region of patients with AD [128] .…”

“…Therefore, the time between fi rst successful radiosynthesis of a new PET radiotracer and its first human use is at least between 5 and 10 years. For example, in the case of the α4β2 nAChR radiotracer (-)-[ 18 F]flubatine, the time between the first report on radiosynthesis [164] and the fi rst report on human use [16] years [210,272] , and for [ 18 F]FEOBV [126] , a radiotracer for the VAChT, it has been almost 20 years [273] . At the beginning of neuroreceptor imaging with PET this transition time was much shorter, in the range of 1-2 years as exemplifi ed by [ 11 C]raclopride [225,274] , 3-N-[ 11 C]methylspiperone [224] , and [ 11 C]fl umazenil [49,275] .…”

PET imaging of cholinergic deficits in rats using [18F]fluoroethoxybenzovesamicol ([18F]FEOBV)

“…On each scanning day, [ 18 F]FEOBV was synthesized using a modified method (Mzengeza et al, 2007) originally described by Mulholland et al (1993). A levo enantiomerically pure precursor (ABX advanced biochemical compounds GmbH) was used, labeled with [ 18 F] using a GE TRACERlab module, resulting in (−)-[ 18 F] FEOBV, which is the only enantiomer showing affinity for VAChT (Mulholland et al, 1998).…”

Deficit in sustained attention following selective cholinergic lesion of the pedunculopontine tegmental nucleus in rat, as measured with both post-mortem immunocytochemistry and in vivo PET imaging with [18F]fluoroethoxybenzovesamicol

“…The [ 18 F]FEOBV was synthesized on each scanning day using a procedure described elsewhere [31], and adapted from the one originally described by Mulholland et al [32]. Rats from the lesion group were scanned using a CTI Concorde R4 microPET for small animals (Siemens CTI).…”