Determination of acid dissociation constants of compounds active at neuronal nicotinic acetylcholine receptors by means of electrophoretic and potentiometric techniques.

The dissociation constants of epiboxidine 2 and a series of bases active at neuronal nicotinic acetylcholine receptors were determined by means of potentiometric and electrophoretic methods, which gave values in good agreement. Although showing different features, the two techniques are complementary for dissociation constant determinations. The choice of the most suitable method is guided by the available amount of sample, its purity, and the time needed for the analysis. The experimental values were compared with the predictions obtained with ACD/pK(a) DB software.