Abstract: The presently claimed subject matter concerns methods and kits for identifying agents that reduce binding of a clostridial neurotoxin to synaptic vesicle glycoprotein 2 (SV2).

Abstract: The present invention accordingly provides in one aspect, novel spiro-oxathiolane/quinuclidine compounds corresponding with the schematic structural formula (I) ##STR1## and geometrical isomers, enantiomers, diastereoisomers, racemates and acid addition salts thereof, wherein one of Y and Z is 0 and the other is S(.dbd.O).sub.n ; n is 0, 1 or 2; R' and R" are each selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkyl, aminoalkyl, C.sub.3-7 cycloalkyl, aryl, diarylmethylol, and alkyl substituted by at least one aryl group, provided that at least R' and R" is other than hydrogen; and each X is hydrogen, or when Y is 0 and Z is S(.dbd.O).sub.n simultaneously, then each X may also be selected from the group consisting of deuterium and tritium, and provided further that when each X is hydrogen, Y is 0 and Z is S simultaneously, then at least one of R' and R" is selected from the group consisting of alkenyl, alkynyl, cyclopropyl, cyclobutyl, cycloheptyl, hydroxyalkyl and aminoalkyl.