Stereochemical preferences for curarimimetic neuromuscular junction blockade IV: Monoquaternary ammonium probes possessing carbon and nitrogen asymmetry.

Two enantiomeric pairs of neuromuscular junction blocking agents were prepared in which an asymmetric carbon atom is adjacent to an asymmetric quaternized nitrogen moiety. The blocking agents were obtained from the enantiomers of laudanosine by stereoselective quaternization with benzyl and ethyl iodides. Curarimimetic potencies were measured with an in vivo cat hypoglossal nerve-tongue muscle preparation. The studies suggest that the asymmetry present in these structures does not lead to significant differences in blocking potency between enantiomers.