Synthesis and in vitro binding affinities of 1-azabicyclic compounds as muscarinic ligands

Two series of compounds, 2 and 3, were synthesized and their binding affini ties were evaluated for the human recombinant muscarinic M-1 receptor subty pe expressed in CHO cells. Comparing their binding affinities for the NMS b inding sites and the Oxo-M binding sites, they were assumed as agonists. In particular, compound 2e was a good ligand for the agonist binding sites wi th an IC50 of 23 nM, which represents over 1585 times stronger binding than for the antagonist binding sites. (C) 2001 Elsevier Science Ltd. All right s reserved.