Discovery and Structure-Activity Relationships of Nociceptin Receptor Partial Agonists That Afford Symptom Ablation in Parkinson's Disease Models

J Med Chem. 2020 Mar 12;63(5):2688-2704. doi: 10.1021/acs.jmedchem.9b02134. Epub 2020 Feb 3.

Abstract

A novel series of C(3)-substituted piperdinylindoles were developed as nociceptin opioid receptor (NOP) partial agonists to explore a pharmacological hypothesis that NOP partial agonists would afford a dual pharmacological action of attenuating Parkinson's disease (PD) motor symptoms and development of levodopa-induced dyskinesias. SAR around the C-3 substituents investigated effects on NOP binding, intrinsic activity, and selectivity and showed that while the C(3)-substituted indoles are selective, high affinity NOP ligands, the steric, polar, and cationic nature of the C-3 substituents affected intrinsic activity to afford partial agonists with a range of efficacies. Compounds 4, 5, and 9 with agonist efficacies between 25% and 35% significantly attenuated motor deficits in the 6-OHDA-hemilesioned rat model of PD. Further, unlike NOP antagonists, which appear to worsen dyskinesia expression, these NOP partial agonists did not attenuate or worsen dyskinesia expression. The NOP partial agonists and their SAR reported here may be useful to develop nondopaminergic treatments for PD.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antiparkinson Agents / chemistry
  • Antiparkinson Agents / pharmacokinetics
  • Antiparkinson Agents / therapeutic use*
  • Caco-2 Cells
  • Disease Models, Animal
  • Humans
  • Indoles / chemistry
  • Indoles / pharmacokinetics
  • Indoles / therapeutic use*
  • Male
  • Nociceptin Receptor
  • Parkinson Disease / drug therapy*
  • Parkinson Disease / metabolism
  • Parkinson Disease / physiopathology
  • Piperidines / chemistry
  • Piperidines / pharmacokinetics
  • Piperidines / therapeutic use
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Opioid / agonists*
  • Receptors, Opioid / metabolism
  • Structure-Activity Relationship

Substances

  • Antiparkinson Agents
  • Indoles
  • Piperidines
  • Receptors, Opioid
  • Nociceptin Receptor