It is known that the inhibition of acetylcholinesterase by isomalathion can proceed either with diethyl succinate as the leaving group or thiomethyl, depending on the specific stereoisomer of isomalathion. Does the mechanism of inhibition of AChE by the Parathion isomer O,S-Diethyl O-4-Nitrophenyl thiophosphate (Or its dimethyl analog) likewise depend on the chirality of the molecule, or is 4-nitrophenyl the leaving group for both stereoisomers?
Reference: Doorn, J. A., Thompson, C. M., Christner, R. B., & Richardson, R. J. (2003). Stereoselective Inactivation ofTorpedo californicaAcetylcholinesterase by Isomalathion: Inhibitory Reactions with (1R)- and (1S)-Isomers Proceed by Different Mechanisms. Chemical Research in Toxicology, 16(8), 958–965. doi:10.1021/tx030026e