Discovery of potent, selective, and metabolically stable 4-(pyridin-3-yl)cinnolines as novel phosphodiesterase 10A (PDE10A) inhibitors

Bioorg Med Chem Lett. 2012 Mar 15;22(6):2262-5. doi: 10.1016/j.bmcl.2012.01.086. Epub 2012 Feb 8.


We report the discovery of 6,7-dimethoxy-4-(pyridin-3-yl)cinnolines as novel inhibitors of phosphodiesterase 10A (PDE10A). Systematic examination and analyses of structure-activity-relationships resulted in single digit nM potency against PDE10A. X-ray co-crystal structure revealed the mode of binding in the enzyme's catalytic domain and the source of selectivity against other PDEs. High in vivo clearance in rats was addressed with the help of metabolite identification (ID) studies. These findings combined resulted in compound 39, a promising potent inhibitor of PDE10A with good in vivo metabolic stability in rats and efficacy in a rodent behavioral model.

MeSH terms

  • Animals
  • Avoidance Learning / drug effects
  • Behavior, Animal / drug effects
  • Binding Sites
  • Coumarins / chemical synthesis*
  • Coumarins / pharmacology
  • Drug Discovery
  • Humans
  • Models, Molecular
  • Phosphodiesterase Inhibitors / administration & dosage
  • Phosphodiesterase Inhibitors / chemical synthesis*
  • Phosphoric Diester Hydrolases / metabolism*
  • Protein Binding
  • Psychotropic Drugs / administration & dosage
  • Psychotropic Drugs / chemical synthesis*
  • Rats
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship


  • Coumarins
  • Phosphodiesterase Inhibitors
  • Psychotropic Drugs
  • PDE10A protein, rat
  • Phosphoric Diester Hydrolases