Lv Xiaotian, Liu Chen, Li Yaobin, Gao Yongxin, Wang Huili, Li Jianzhong, Guo Baoyuan
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
Ecotoxicol Environ Saf. 2014 Sep;107:71-6. doi: 10.1016/j.ecoenv.2014.02.013. Epub 2014 Jun 4.
Stereoselectivity in bioaccumulation and excretion of stereoisomers of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae through dietary exposure was investigated. Liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method that use a ChiralcelOD-3R[cellulosetris-Tris-(3, 5-dichlorophenyl-carbamate)] chromatography column was applied to carry out chiral separation of the stereoisomers. Wheat bran was spiked with racemic epoxiconazole at two dose levels of 20mg/kg and 2mg/kg (dry weight) to feed T. molitor larvae. The results showed that both the doses of epoxiconazole were taken up by Tenebrio molitor larvae rapidly at the initial stages. There was a significant trend of stereoselective bioaccumulation in the larvae with a preferential accumulation of (-)-epoxiconazole in the 20mg/kg dose. The stereoselectivity in bioaccumulation in the 2mg/kg dosage was not obvious compared to the 20mg/kg group. Results of excretion indicated an active excretion is an important pathway for the larvae to eliminate epoxiconazole which was a passive transport process with non stereoselectivity. The faster elimination might be the reason for the low accumulation of epoxiconazole, as measured by bioaccumulation factor (BAF).
研究了黄粉虫（Tenebrio molitor）幼虫通过饮食接触对环氧唑立体异构体进行生物累积和排泄的立体选择性。采用使用ChiralcelOD-3R[纤维素三（3,5-二氯苯基氨基甲酸酯）]色谱柱的液相色谱串联质谱法（HPLC-MS/MS）对立体异构体进行手性分离。用两种剂量水平（20mg/kg和2mg/kg干重）的外消旋环氧唑加标麦麸来喂养黄粉虫幼虫。结果表明，两种剂量的环氧唑在初始阶段均被黄粉虫幼虫迅速吸收。在20mg/kg剂量组中，幼虫存在显著的立体选择性生物累积趋势，优先累积（-）-环氧唑。与20mg/kg组相比，2mg/kg剂量下生物累积的立体选择性不明显。排泄结果表明，主动排泄是幼虫消除环氧唑的重要途径，这是一个非立体选择性的被动转运过程。通过生物累积因子（BAF）测量，较快的消除可能是环氧唑累积量低的原因。
