Design, synthesis, and action of oxotremorine-related hybrid-type allosteric modulators of muscarinic acetylcholine receptors

J Med Chem. 2006 Jan 12;49(1):366-72. doi: 10.1021/jm050769s.


A novel series of muscarinic receptor ligands of the hexamethonio-type was prepared which contained, on one side, the phthalimidopropane or 1,8-naphthalimido-2,2-dimethylpropane moiety typical for subtype selective allosteric antagonists and, on the other, the acetylenic fragment typical for the nonselective orthosteric muscarinic agonists oxotremorine, oxotremorine-M, and related muscarinic agonists. Binding experiments in M(2) receptors using [(3)H]N-methylscopolamine as an orthosteric probe proved an allosteric action of both groups of hybrids, 7a-10a and 8b-10b. The difference in activity between a-group and b-group hybrids corresponded with the activity difference between the allosteric parent compounds. In M(1)-M(3) muscarinic isolated organ preparations, most of the hybrids behaved as subtype selective antagonists. [(35)S]GTPgammaS binding assays using human M(2) receptors overexpressed in CHO cells revealed that a weak intrinsic efficacy was preserved in 8b-10b. Thus, attaching muscarinic allosteric antagonist moieties to orthosteric muscarinic agonists may lead to hybrid compounds in which functions of both components are mixed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation / drug effects
  • Animals
  • CHO Cells
  • Cricetinae
  • Drug Design
  • Guinea Pigs
  • Humans
  • Ligands
  • Male
  • Molecular Structure
  • Oxotremorine / analogs & derivatives
  • Oxotremorine / chemical synthesis*
  • Oxotremorine / pharmacology*
  • Phthalimides / chemistry
  • Pyridones / chemistry
  • Rabbits
  • Receptors, Muscarinic / biosynthesis
  • Receptors, Muscarinic / drug effects*
  • Structure-Activity Relationship


  • Ligands
  • Phthalimides
  • Pyridones
  • Receptors, Muscarinic
  • Oxotremorine