5-(5-(6-[(11)C]methyl-3,6-diazabicyclo[3.2.0]heptan-3-yl)pyridin-2-yl)-1H-indole as a potential PET radioligand for imaging cerebral α7-nAChR in mice

Bioorg Med Chem. 2012 Jun 15;20(12):3698-702. doi: 10.1016/j.bmc.2012.04.056. Epub 2012 May 4.

Abstract

The radiosynthesis and in vivo evaluation of 5-(5-(6-[(11)C]methyl-3,6-diazabicyclo[3.2.0]heptan-3-yl)pyridin-2-yl)-1H-indole [(11)C]rac-(1), a potential PET tracer for α7 nicotinic acetylcholine receptors (α7-nAChR), are described. Syntheses of the nonradioactive standard rac-1 and corresponding desmethyl precursor 7 were achieved in several reaction steps. Radiomethylation of 7 with [(11)C]CH(3)I afforded [(11)C]rac-1 in an average radiochemical yield of 30 ± 5% (n=5) with high radiochemical purity and an average specific radioactivity of 444 ± 74 GBq/μmol (n=5). The total synthesis time was 30 min from end-of-bombardment. Biodistribution studies in mice showed that [(11)C]rac-1 penetrates the blood-brain barrier and specifically labels neuronal α7-nAChRs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / diagnostic imaging*
  • Brain / metabolism
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Indoles* / antagonists & inhibitors
  • Ligands
  • Mice
  • Mice, Inbred Strains
  • Molecular Structure
  • Positron-Emission Tomography*
  • Pyridines* / antagonists & inhibitors
  • Quinuclidines / pharmacology
  • Radiopharmaceuticals* / antagonists & inhibitors
  • Radiopharmaceuticals* / chemistry
  • Receptors, Nicotinic / analysis*
  • Receptors, Nicotinic / metabolism
  • alpha7 Nicotinic Acetylcholine Receptor

Substances

  • 5-(5-(6-((11)C)methyl-3,6-diazabicyclo(3.2.0)heptan-3-yl)pyridin-2-yl)-1H-indol
  • Bridged Bicyclo Compounds, Heterocyclic
  • Chrna7 protein, mouse
  • Indoles
  • Ligands
  • N-(1-azabicyclo(2.2.2)oct-3-yl)furo(2,3-c)pyridine-5-carboxamide
  • Pyridines
  • Quinuclidines
  • Radiopharmaceuticals
  • Receptors, Nicotinic
  • alpha7 Nicotinic Acetylcholine Receptor