The 23 quaternary and tertiary protoberberines related to berberine were te
sted for in vitro and/or in vivo fungicidal and herbicidal activities. Amon
g the compounds tested, there was some activity observed with some of only
the protoberberinium salts, but not sufficiently strong or broad spectrum f
or agrochemical use. From the structure-activity point of view, some featur
es can be pointed out.