Synthesis and Biological Evaluation of Novel Epibatidine Analogues

In an effect to develop for more selective neuronal nicotinic acetylcholine receptor analgesics that have less toxicity and adverse side effects relative to epibatidine, three new classes of epibatidine analogues were synthesized and evaluated in vitro as potential potent selective nAChR ligands. Specifically, three analogues of epibatidine were synthesized to explore the structure-activity relationships of epibatidine relative to neuromuscular blocking activity as well as nAChRs. Both quaternary epibatidine analogues 2 and bis-epibatidine derivative 3 exhibited high binding affinity relative to nicotine. In addition, a new series of 2-(hydroxyalkylpyridyl)-7-azabicyclo[2.2.1]heptane derivatives were synthesized and evaluated as potential ligands for nicotinic acetylcholine receptors. Moreover, two rigid 2-acetoxy-7-azabicyclo[2.2.1]heptane analogues have been prepared to study the binding conformation of acetylcholine at the active sites of the nicotinic acetylcholine receptors