ABSTRACT
Positive modulators at the benzodiazepine site of α2- and α3-containing GABA(A) receptors are believed to be anxiolytic. Through oocyte voltage clamp studies, we have discovered two series of compounds that are positive modulators at α2-/α3-containing GABA(A) receptors and that show no functional activity at α1-containing GABA(A) receptors. We report studies to improve this functional selectivity and ultimately deliver clinical candidates. The functional SAR of cinnolines and quinolines that are positive allosteric modulators of the α2- and α3-containing GABA(A) receptors, while simultaneously neutral antagonists at α1-containing GABA(A) receptors, is described. Such functionally selective modulators of GABA(A) receptors are expected to be useful in the treatment of anxiety and other psychiatric illnesses.
Subject(s)
Receptors, GABA-A/chemistry , Allosteric Regulation , Anti-Anxiety Agents/chemical synthesis , Anti-Anxiety Agents/chemistry , Anti-Anxiety Agents/pharmacology , Benzodiazepines/chemistry , GABA-A Receptor Antagonists/chemical synthesis , GABA-A Receptor Antagonists/chemistry , GABA-A Receptor Antagonists/pharmacology , Heterocyclic Compounds, 2-Ring/chemistry , Quinolines/chemistry , Receptors, GABA-A/metabolism , Structure-Activity RelationshipABSTRACT
Positive modulators at benzodiazepine sites of α2- and α3-containing GABA(A) receptors are believed to be anxiolytic. Negative allosteric modulators of α5-containing GABA(A) receptors enhance cognition. By oocyte two-electrode voltage clamp and subsequent structure-activity relationship studies, we discovered cinnoline and quinoline derivatives that were both positive modulators at α2-/α3-containing GABA(A) receptors and negative modulators at α5-containing GABA(A) receptors. In addition, these compounds showed no functional activity at α1-containing GABA(A) receptors. Such dual functional modulators of GABA(A) receptors might be useful for treating comorbidity of anxiety and cognitive impairments in neurological and psychiatric illnesses.