Radiosynthesis and evaluation of novel 18F labeled PET ligands for imaging monoacylglycerol lipase

  • Eur J Med Chem. 2025 Mar 5:285:117246. doi: 10.1016/j.ejmech.2025.117246.
Yinlong Li  1 ,  Wakana Mori  2 ,  Ahmad Chaudhary  1 ,  Chunyu Zhao  1 ,  Tomoteru Yamasaki  2 ,  Zachary Zhang  1 ,  Siyan Feng  1 ,  Tim Ware  3 ,  Jian Rong  1 ,  Masayuki Fujinaga  2 ,  Jiahui Chen  1 ,  Katsushi Kumata  2 ,  Yiding Zhang  2 ,  Kuan Hu  2 ,  Lin Xie  2 ,  Xin Zhou  1 ,  Zhendong Song  1 ,  Yabiao Gao  1 ,  Zhenkun Sun  4 ,  Jimmy S Patel  5 ,  Chuangyan Zhai  1 ,  Katherine Y Yuan  1 ,  Thomas L Collier  1 ,  Chongzhao Ran  6 ,  Ludovic Collin  7 ,  Achi Haider  7 ,  Uwe Grether  7 ,  Matthias B Wittwer  7 ,  Benjamin F Cravatt  3 ,  Ming-Rong Zhang  8 ,  Steven H Liang  9
Affiliations
  • 1. Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Road, Atlanta, GA, 30322, United States.
  • 2. Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Sciences, National Institutes for Quantum Science and Technology, Chiba, 263-8555, Japan.
  • 3. The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, 92037, United States.
  • 4. Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, 30322, United States.
  • 5. Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Road, Atlanta, GA, 30322, United States; Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, 30322, United States.
  • 6. Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, United States.
  • 7. F. Hoffmann -La Roche Ltd, Roche. Innovation Center Basel, Switzerland by Roche Pharma Research and Early Development (pRED), Roche Innovation Center Basel, 4070, Basel, Switzerland.
  • 8. Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Sciences, National Institutes for Quantum Science and Technology, Chiba, 263-8555, Japan. Electronic address: [email protected].
  • 9. Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Road, Atlanta, GA, 30322, United States. Electronic address: [email protected].
PMID: 39793441 DOI: 10.1016/j.ejmech.2025.117246
Abstract

Monoacylglycerol Lipase (MAGL) is a 33 kDa cytosolic serine hydrolase that is widely distributed in the central nervous system and peripheral tissues. MAGL hydrolyzes monoacylglycerols into Fatty Acids and glycerol, playing a crucial role in endocannabinoid degradation. Inhibition of MAGL in the brain elevates levels of 2-arachidonoylglycerol and leads to decreased pro-inflammatory prostaglandin and thromboxane production. As such, MAGL is considered a potential target for treating neuropsychiatric disorders, metabolic syndromes, and Cancer. Based on a novel spirocyclic system, we synthesized two fluorinated carbamate scaffolds as reversible MAGL inhibitors (epimers: (R)-6, IC50 = 18.6 nM and (S)-6, IC50 = 1.6 nM). In vitro autoradiography studies of [18F](R)-6 (codenamed [18F]MAGL-2304) and [18F](S)-6 (codenamed [18F]MAGL-2305) demonstrated heterogeneous distribution and specific binding affinity to MAGL-rich brain regions. Autoradiography with MAGL knockout mouse brain tissues confirmed the binding specificity of [18F](S)-6. Dynamic PET imaging studies revealed that [18F](S)-6 exhibited limited brain uptake and homogenous distribution in rat Brains. In vivo P-gp inhibition enhanced [18F](S)-6 uptake in the brain, suggesting that [18F](S)-6 constitutes a P-gp efflux substrate. This research could provide new directions in the design of MAGL PET ligands that are based on spirocyclic scaffolds.

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