Enantioselective acetylcholinesterase inhibition of the organophosphorous insecticides profenofos, fonofos, and crotoxyphos

摘要: A large number of organophosphorous insecticides (OPs) are chiral compounds, and yet enantioselectivity in their environmental fate effects is rarely addressed. In the present study, we isolated individual enantiomers three OPs, profenofos, fonofos, crotoxyphos, evaluated inhibition acetylcholinesterase (AChE). Acetylcholinesterase by racemates was determined vivo aquatic invertebrate Daphnia magna Japanese medaka (Oryzias latipes) as well vitro with electric eel (Electrophorus electricus) human recombinant AChEs. The overall results showed variable sensitivity between AChE enzymes from different species magnitude enzyme inhibition. (—)-enantiomer profenofos 4.3- to 8.5-fold more inhibitory vivo, whereas (—)-fonofos 2.3- 29-fold potent than corresponding (+)-enantiomer. (+)-enantiomer crotoxyphos 1.1- 11-fold (—)-enantiomer. contrast, (+)-profenofos be 2.6- 71.8-fold (—)-crotoxyphos 1.6- 1.9-fold active reversed direction observed assays suggests within toxicodynamic processes such uptake, biotransformation, or elimination. Findings study provide evidence OPs nontarget organisms indicate need consider individually when assessing risk these pesticides.