Molecular Imaging of Monoamine Oxidase A Expression in Highly Aggressive Prostate Cancer: Synthesis and Preclinical Evaluation of Positron Emission Tomography Tracers.

The role of monoamine oxidase A (MAO-A) in the aggressiveness of prostate cancer (PCa) has been established in recent years. The molecular imaging of MAO-A expression could offer a noninvasive tool for the visualization and quantification of highly aggressive PCa. This study reports the synthesis and preclinical evaluation of C- and F-labeled MAO-A inhibitors as positron emission tomography (PET) tracers for proof-of-concept studies in animal models of PCa.

Development and characterization of two novel Ga-labelled neuropeptide Y short analogues with potential application in breast cancer imaging.

In vivo receptor targeting with radiolabelled peptide-based probes is an attractive approach for the development of novel radiotracers for molecular imaging. This work presents the development and characterization of two novel neuropeptide Y analogues labelled with a positron emitter Ga, for potential use in breast cancer imaging. Both analogues share the same amino acid sequence and were derivatized with NOTA through either a lysine linker (L1) or an acetylated lysine (L2).

An efficient preparation of labelling precursor of [C]L-deprenyl-D and automated radiosynthesis.

Background: The synthesis of [C]L-deprenyl-D for imaging of astrocytosis with positron emission tomography (PET) in neurodegenerative diseases has been previously reported. [C]L-deprenyl-D radiosynthesis requires a precursor, L-nordeprenyl-D, which has been previously synthesized from L-amphetamine as starting material with low overall yields. Here, we present an efficient synthesis of L-nordeprenyl-D organic precursor as free base and automated radiosynthesis of [C]L-deprenyl-D for PET imaging of astrocytosis.

Automated radiosynthesis of [(11)C]L-deprenyl-D2 and [(11)C]D-deprenyl using a commercial platform.

Two (11)C-labelled PET tracers, (R)-N-[(11)C]methyl-N-(3,3-dideuteropropargyl)-1-phenylpropan-2-amine ([(11)C]L-deprenyl-D2, [(11)C]DED) and (S)-N-[(11)C]methyl-N-propargyl-1-phenylpropan-2-amine ([(11)C]D-deprenyl, [(11)C]DDE) were synthesised. One step N-alkylation with [(11)C]MeI or [(11)C]MeOTf was performed using the automated platform TRACERlab® FX-C Pro. The labelled products were obtained with (37±15)% (n=10) (end of synthesis, decay corrected from [(11)C]MeI) radiochemical yields from [(11)C]MeI after 38±3min synthesis time.