Ma Yun, Chen Linhua, Lu Xianting, Chu Huadong, Xu Chao, Liu Weiping
Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China.
Ecotoxicol Environ Saf. 2009 Oct;72(7):1913-8. doi: 10.1016/j.ecoenv.2009.07.005. Epub 2009 Aug 3.
Synthetic pyrethroids (SPs) are a family of chiral insecticides with a large number of stereoisomers. Fenvalerate (FV) is one of the most potent pyrethroid insecticides, controlling a wide range of insect pests in agricultural fields, public health situations and animal houses. FV contains two chiral centers. In this study, four stereoisomers of FV were absolutely separated by high-performance liquid chromatography with a commercial chiral column, CHIRALCEL OJ-H, using n-hexane containing 1,2-dichloroethane and ethanol as mobile phase. Toxicity assays of each isomer and racemate of FV were performed using Daphnia magna (D. magna), zebrafish (Danio rerio) and zebrafish embryo-larval. In the acute toxicity of D. magna, significant differences were observed: the 24h EC(50) of alphaS-2S-FV was 51 times more toxic than the alphaR-2R-FV, and the 48 h LC(50) results showed that the alphaS-2S-FV was 99 times more toxic than alphaR-2R-FV. In the toxicity assay of D. rerio, dramatic differences were also found: the LC(50) value of alphaS-2S-FV was 17, 22, 39 and 56 times more toxic than the alphaR-2R-FV at 24, 48, 72 and 96 h, respectively. The assays of 4-day-old zebrafish embryo-larval showed that the exposure to FV enantioselectively induced crooked body, yolk sac edema and pericardial edema and that the alphaS-2S-FV was 3.8 times stronger than the other isomers in 96-h mortality. The results indicate that the enantiomeric differences should be taken into consideration in assessing the ecological effects of SPs.
合成拟除虫菊酯（SPs）是一类具有大量立体异构体的手性杀虫剂。氰戊菊酯（FV）是最有效的拟除虫菊酯杀虫剂之一，可控制农业领域、公共卫生环境和动物饲养场中的多种害虫。FV含有两个手性中心。在本研究中，使用商业手性柱CHIRALCEL OJ-H，以含有1,2-二氯乙烷和乙醇的正己烷为流动相，通过高效液相色谱法将FV的四种立体异构体完全分离。使用大型溞（D. magna）、斑马鱼（Danio rerio）和斑马鱼胚胎幼体对FV的每种异构体和外消旋体进行了毒性测定。在大型溞的急性毒性试验中，观察到显著差异：αS-2S-FV的24小时半数有效浓度（EC(50)）比αR-2R-FV毒性高51倍，48小时半数致死浓度（LC(50)）结果表明，αS-2S-FV比αR-2R-FV毒性高99倍。在斑马鱼的毒性试验中，也发现了显著差异：αS-2S-FV的LC(50)值在24、48、72和96小时分别比αR-2R-FV毒性高17、22、39和56倍。对4日龄斑马鱼胚胎幼体的试验表明，暴露于FV会对其产生对映体选择性诱导的身体弯曲、卵黄囊水肿和心包水肿，并且在96小时死亡率方面，αS-2S-FV比其他异构体强3.8倍。结果表明，在评估SPs的生态效应时应考虑对映体差异。
