Exploration of the structure-activity relationship of a novel tetracyclic class of TSPO ligands-potential novel positron emitting tomography imaging agents

Bioorg Med Chem Lett. 2013 Apr 15;23(8):2368-72. doi: 10.1016/j.bmcl.2013.02.057. Epub 2013 Feb 24.


A series of novel TSPO ligands based on the tetracyclic class of translocator protein (TSPO) ligands first described by Okubo et al. was synthesised and evaluated as potential positron emitting tomography (PET) ligands for imaging TPSO in vivo. Fluorine-18 labelling of the molecules was achieved using direct radiolabelling or synthon based labelling approaches. Several of the ligands prepared have promising profiles as potential TSPO PET imaging ligands.

MeSH terms

  • Animals
  • Fluorine Radioisotopes / chemistry
  • Isotope Labeling / methods
  • Ligands
  • Positron-Emission Tomography / methods*
  • Protein Transport
  • Rats
  • Receptors, GABA / analysis*
  • Receptors, GABA / chemistry
  • Receptors, GABA / metabolism*
  • Structure-Activity Relationship


  • Fluorine Radioisotopes
  • Ligands
  • Receptors, GABA
  • TSPO protein, human