Structure-Activity Relationships and Computational Investigations into the Development of Potent and Balanced Dual-Acting Butyrylcholinesterase Inhibitors and Human Cannabinoid Receptor 2 Ligands with Pro-Cognitive in Vivo Profiles

J Med Chem. 2018 Feb 22;61(4):1646-1663. doi: 10.1021/acs.jmedchem.7b01760. Epub 2018 Feb 5.

Abstract

The enzyme butyrylcholinesterase (BChE) and the human cannabinoid receptor 2 (hCB2R) represent promising targets for pharmacotherapy in the later stages of Alzheimer's disease. We merged pharmacophores for both targets into small benzimidazole-based molecules, investigated SARs, and identified several dual-acting ligands with a balanced affinity/inhibitory activity and an excellent selectivity over both hCB1R and hAChE. A homology model for the hCB2R was developed based on the hCB1R crystal structure and used for molecular dynamics studies to investigate binding modes. In vitro studies proved hCB2R agonism. Unwanted μ-opioid receptor affinity could be designed out. One well-balanced dual-acting and selective hBChE inhibitor/hCB2R agonist showed superior in vivo activity over the lead CB2 agonist with regards to cognition improvement. The data shows the possibility to combine a small molecule with selective and balanced GPCR-activity/enzyme inhibition and in vivo activity for the therapy of AD and may help to rationalize the development of other dual-acting ligands.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / drug therapy*
  • Benzimidazoles / agonists
  • Benzimidazoles / chemistry
  • Benzimidazoles / pharmacology
  • Benzimidazoles / therapeutic use
  • Butyrylcholinesterase / chemistry*
  • Cognition / drug effects
  • Enzyme Inhibitors / chemistry
  • Humans
  • Ligands
  • Protein Binding
  • Receptor, Cannabinoid, CB2 / agonists*
  • Receptors, G-Protein-Coupled
  • Structure-Activity Relationship

Substances

  • Benzimidazoles
  • CNR2 protein, human
  • Enzyme Inhibitors
  • Ligands
  • Receptor, Cannabinoid, CB2
  • Receptors, G-Protein-Coupled
  • Butyrylcholinesterase