Enantioselective environmental behavior and cytotoxicity of chiral acaricide cyflumetofen.

Enantioselective dissipation behavior of the new acaricide cyflumetofen (CYF) in citrus and soil, and its cytotoxicity to human liver hepatocellular carcinoma (HepG2) cells was investigated for the first time. The results of degradation experiment showed that roughly similar half-lives of (-)-CYF and (+)-CYF were achieved in citrus (16.5 and 19.8 d) and soil (6.37 and 6.99 d), respectively. EF values varied from 0.50 to 0.42 in citrus and from 0.49 to 0.48 in soil, indicating that slightly enantioselective degradation happened during experiment period. Moreover, indexes of MTT, LDH, ROS, MDA, SOD, and CAT were used to evaluate enantioselective cytotoxicity and oxidative stress of CYF enantiomers to HepG2 cells. Dose- and structure form-dependent phenomenon was observed with toxicity orders of (-)-CYF > rac-CYF > (+)-CYF. Despite the similar environmental degradation behavior, the toxicities of CYF enantiomers showed great difference, suggesting that (+)-CYF might be developed as potential substitute of rac-CYF for safety consideration.