Pharmacological Characterization of Chiral Muscarinic Antagonists cis-2-Phenyl-2-cyclohexyl-r-5-[(dimethylamino)-methyl]1,3-oxathiolane-3-oxide Methiodide

. Cis-2-phenyl-2-cyclohexyl-r-5 [(dimethylamino)-methyl]-1,3-oxathiolane cis [(±)1] and trans [(±)2] 3-oxide methiodides together with the enantiomers (+)2 and (-)2 where evaluated for their antimuscarinic activity in functional (in vivo and in vitro) and in binding studies. The results indicate that in all the receptor subtypes the trans isomer (±)2 is more active than the cis one (±)1. Of the two enantiomers, (+)2 displays the highest affinity while the values of eudismic ratios, although large, are similar for all the subtypes. Furthermore, the tested oxathiolanes show a small degree of selectivity in binding studies while in functional studies selectivity is absent.