[Anticholinesterase properties of benzo(f)quinolinium derivatives]

"In vitro" studies have demonstrated that methyl-p-toluene sulfonates of 1-methyl-(ethyl)-3-aryl-benzo(f)quinolinium are highly efficient inhibitors of cholinesterases, the inhibition constants (Ki) for acetylcholinesterase and butyrylcholinesterase being equal to 2.20 +/- 0.49 and 9.43 +/- 0.39 mkM, respectively. The effect of these inhibitors on the enzyme is of competitive - non-competitive type. A certain role in benzo(f)quinoline binding to acetylcholinesterase apparently belongs to the interaction of substituents in the phenyl nucleus with the anionic sites located outside the active surface of the enzyme.