Identification of novel α4β2-nicotinic acetylcholine receptor (nAChR) agonists based on an isoxazole ether scaffold that demonstrate antidepressant-like activity

J Med Chem. 2012 Jan 26;55(2):812-23. doi: 10.1021/jm201301h. Epub 2012 Jan 4.

Abstract

There is considerable evidence to support the hypothesis that the blockade of nAChR is responsible for the antidepressant action of nicotinic ligands. The nicotinic acetylcholine receptor (nAChR) antagonist, mecamylamine, has been shown to be an effective add-on in patients that do not respond to selective serotonin reuptake inhibitors. This suggests that nAChR ligands may address an unmet clinical need by providing relief from depressive symptoms in refractory patients. In this study, a new series of nAChR ligands based on an isoxazole-ether scaffold have been designed and synthesized for binding and functional assays. Preliminary structure-activity relationship (SAR) efforts identified a lead compound 43, which possesses potent antidepressant-like activity (1 mg/kg, IP; 5 mg/kg, PO) in the classical mouse forced swim test. Early stage absorption, distribution, metabolism, excretion, and toxicity (ADME-Tox) studies also suggested favorable drug-like properties, and broad screening toward other common neurotransmitter receptors indicated that compound 43 is highly selective for nAChRs over the other 45 neurotransmitter receptors and transporters tested.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antidepressive Agents / chemical synthesis*
  • Antidepressive Agents / chemistry
  • Antidepressive Agents / pharmacology
  • Blood Proteins / metabolism
  • Cytochrome P-450 Enzyme Inhibitors
  • ERG1 Potassium Channel
  • Ether-A-Go-Go Potassium Channels / antagonists & inhibitors
  • HEK293 Cells
  • Humans
  • Isoxazoles / chemical synthesis*
  • Isoxazoles / chemistry
  • Isoxazoles / pharmacology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Microsomes, Liver / metabolism
  • Nicotinic Agonists / chemical synthesis*
  • Nicotinic Agonists / chemistry
  • Nicotinic Agonists / pharmacology
  • Protein Binding
  • Radioligand Assay
  • Rats
  • Receptors, Nicotinic / metabolism*
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Antidepressive Agents
  • Blood Proteins
  • Cytochrome P-450 Enzyme Inhibitors
  • ERG1 Potassium Channel
  • Ether-A-Go-Go Potassium Channels
  • Isoxazoles
  • Nicotinic Agonists
  • Receptors, Nicotinic
  • nicotinic receptor alpha4beta2