Acetylethylcholine mustard hydrochloride is an inhibitor of choactase (choline acetyl-transferase). Acetylethylcholine mustard hydrochloride is also a precursor for ethylcholine mustard aziridinium ion (AF-64A). This compound is an irreversible ligand for the high affinity choline transport system. Acetylethylcholine mustard hydrochloride is also a specific presynaptic long action cholinotoxin.