The present invention provides an excellent acetylcholinesterase inhibitor.
That is, it provides an acetylcholinesterase inhibitor comprising a
1-benzylpyridinium salt represented by the following formula:
##STR1##
wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same as or different
from each other and each represents a hydrogen atom, a halogen atom, a
hydroxyl group, a nitrile group, a C.sub.1-6 alkyl group, a C.sub.1-6
alkoxy group etc.; R.sup.5 represents a hydrogen atom, a halogen atom
etc.; the partial structure:
##STR2##
is a group represented by the formula >C(R.sup.6)--CH.sub.2 -- (wherein
R.sup.6 is a hydrogen atom or a halogen atom) or >C.dbd.CH--; X-
represents a halide ion or organic sulfonic acid ion; and m is 0 or an
integer from 1 to 5.
