Enantioselective Acute Toxicity Effects and Bioaccumulation of Furalaxyl in the Earthworm ( Eisenia foetida )

The enantioselectivities of individual enantiomers of furalaxyl in acute toxicity and bioaccumulation in the earthworm ( Eisenia foetida ) were studied. The acute toxicity was tested by filter paper contact test. After 48 h of exposure, the calculated LC 50 values of the R ‐form, rac ‐form, and S ‐form were 2.27, 2.08, and 1.22 µg cm ‐2 , respectively. After 72 h of exposure, the calculated LC 50 values were 1.90, 1.54, and 1.00 µg cm ‐2 , respectively. Therefore, the acute toxicity of furalaxyl enantiomers was enantioselective . During the bioaccumulation experiment, the enantiomer fraction of furalaxyl in earthworm tissue was observed to deviate from 0.50 and maintained a range of 0.55–0.60; in other words, the bioaccumulation of furalaxyl was enantioselective in earthworm tissue with a preferential accumulation of S ‐furalaxyl. The uptake kinetic of furalaxyl enantiomers fitted the first‐order kinetics well and the calculated kinetic parameters were consistent with the low accumulation efficiency. Chirality 26:307–312, 2014 . © 2014 Wiley Periodicals, Inc.