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N-(3,4-Dimethylisoxazol-5-yl)piperazine-4-[4-(2-fluoro-4-[(11)C]methylphenyl)thiazol-2-yl]-1-carboxamide: A Promising Positron Emission Tomography Ligand for Fatty Acid Amide Hydrolase

Yoko Shimoda, Masayuki Fujinaga, Akiko Hatori, Joji Yui, Yiding Zhang, Nobuki Nengaki, Yusuke Kurihara, Tomoteru Yamasaki, Lin Xie, Katsushi Kumata, Hideki Ishii, Ming-Rong Zhang

Bioorg Med Chem. 2016 Feb 15;24(4):627-34.

PMID: 26740152

Abstract:

To visualize fatty acid amide hydrolase (FAAH) in brain in vivo, we developed a novel positron emission tomography (PET) ligand N-(3,4-dimethylisoxazol-5-yl)piperazine-4-[4-(2-fluoro-4-[(11)C]methylphenyl)thiazol-2-yl]-1-carboxamide ([(11)C]DFMC, [(11)C]1). DFMC (1) was shown to have high binding affinity (IC50: 6.1nM) for FAAH. [(11)C]1 was synthesized by C-(11)C coupling reaction of arylboronic ester 2 with [(11)C]methyl iodide in the presence of Pd catalyst. At the end of synthesis, [(11)C]1 was obtained with a radiochemical yield of 20±10% (based on [(11)C]CO2, decay-corrected, n=5) and specific activity of 48-166GBq/μmol. After the injection of [(11)C]1 in mice, high uptake of radioactivity (>2% ID/g) was distributed in the lung, liver, kidney, and brain, organs with high FAAH expression. PET images of rat brains for [(11)C]1 revealed high uptakes in the cerebellar nucleus (SUV=2.4) and frontal cortex (SUV=2.0), two known brain regions with high FAAH expression. Pretreatment with the FAAH-selective inhibitor URB597 reduced the brain uptake. Higher than 90% of the total radioactivity in the rat brain was irreversible at 30min after the radioligand injection. The present results indicate that [(11)C]1 is a promising PET ligand for imaging of FAAH in living brain.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
IAR42410445 Deoxycholic-2,2,4,4,11,11-d6 acid Deoxycholic-2,2,4,4,11,11-d6 acid Price
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