18F-Labeled sufentanil for PET-imaging of μ-opioid receptors

The synthesis of an 18F-labeled sufentanil analogue with apparent high μ-opioid receptor selectivity is reported. Intravenous injection of N-[4-(methoxymethyl)-1-[2-(2-thienyl)ethyl]-4-piperidinyl]-N-phenyl-2-(±)-[18F]fluoropropan-amide in mice resulted in high brain uptake and a regional brain activity distribution corresponding to the μ-opioid receptor expression pattern. The developed ligand is a promising tracer for extended protocols in μ-opioid receptor mapping and quantitation with positron emission tomography.