Cholinesterases from Plant Tissues: II. Inhibition of Bean Cholinesterase by 2-Isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine Carboxylate Methyl Chloride (AMO-1618).

2-Isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride (AMO-1618) inhibits the activity of a cholinesterase isolated from mung bean (Phaseolus aureus) roots at concentrations comparable to those which retard growth and inhibit development of secondary roots of bean seedlings. Fifty per cent inhibition of the cholinesterase activity occurred at 0.21 mm. Inhibition of the cholinesterase is non-competitive and irreversible. The growth retardant seems to be a specific cholinesterase inhibitor since it has no effect on non-choline esterases.