Inhibitors of choline acetyltransferase as potential insecticides

Abstract

Abstract Choline acetyltransferase (E.C.2.3.1.6) catalyses the synthesis of acetylcholine and is therefore a target for a new insecticide. We have prepared a variety of compounds, mainly choline analogues, as inhibitors of this enzyme. One of these, 2‐isothiocyanatoethyltrimethylammonium iodide, has a K i of 0.06 μ M ( K m for choline is 150 μ M ) and is apparently the most powerful inhibitor known for this enzyme. Although some of our compounds are insecticidal we believe, on the basis of electrophysiological studies, that they act, not on choline acetyltransferase, but on the acetylcholine receptor of the insect.