Johnson_1993_Chem.Biol.Interact_87_133

Resolved isomers of O-n-hexyl-S-methylphosphorothioamidate (HXM) which had been synthesised by separate stereospecific routes were analysed by chiral glc: about 2-3% of R-(+) isomer was found in the S-(-) sample and accounted for nearly all the inhibitory power against neuropathy target esterase. Incubation of racemic HXM with rabbit serum led to slow but very specific disposal of R-(+) isomer to undetectable levels with very slight loss of S-(-): the rate of disposal was roughly estimated to be about 1% of the published rate of hydrolysis of paraoxon. Incubation with crystalline chymotrypsin caused a preferential but not totally selective disposal of S-(-) isomer.