Abstract: Optimized geometries of twenty three pyridylamine ligands for the nicotinic acetylcholine receptor are obtained by using simulated annealing method of molecular dynamics. Then these complexes are optimized by molecular mechanics and semi-empirical quantum mechanics method-AM1 and the electronic structures are calculated. The result reveals that the value of pKi has some relationship with the energy of lowest unoccupied molecular orbital, charge on the pyridyl group and molecular conformation.

Key words: Simulated annealing method, AM1 method, Nicotinic acetylcholine receptor(nAChRs), Pyridylamine ligands