Shen Qiuxuan, Li Jitong, Xu Peng, Li Wei, Zhuang Guoqiang, Wang Yinghuan
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, PR China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, PR China.
Ecotoxicol Environ Saf. 2017 Sep;143:159-165. doi: 10.1016/j.ecoenv.2017.05.024. Epub 2017 May 21.
Chinese lizards (Eremias argus) were exposed to separated R-(-)-triadimefon, S-(+)-triadimefon and racemic triadimefon to evaluate enantioselective accumulation of triadimefon. After single oral administration of R-(-)-triadimefon, S-(+)-triadimefon and racemic triadimefon, the time-concentration curves in different tissues were found to be different. Triadimefon enantiomers crossed the blood-brain barrier and brain is a main target organ. The residues of triadimefon enantiomers in fat were highest after 24h indicating that fat was the main tissue of accumulation. In racemic triadimefon exposure group, the enantiomer fractions of R-(-)-triadimefon in different tissues showed that the differences between R-(-)-triadimefon and S-(+)-triadimefon were significant in absorption and metabolism, but the differences became smaller in exclusion and accumulation. From the results of mathematical models, S-(+)-triadimefon was absorbed and eliminated faster than R-(-)-triadimefon, and R-(-)-triadimefon was easily distributed in the tissues and more easily converted into its metabolites. Furthermore, among the four enantiomers of triadimenol, SR-(-)-triadimenol produced by S-(+)-triadimefon may have the highest fungicidal activity and the strongest biological toxicity, RR-(+)-triadimenol produced by R-(-)-triadimefon was most likely to bioaccumulate in lizard. Identifying toxicological effects and dose-response relationship of SR-(-)-triadimenol and RR-(+)-triadimenol will help fully assess the risk of TF enantiomers use in the future. The results enrich and supplement the knowledge of the environmental fate of triadimefon enantiomers.
将中国石龙子（丽斑麻蜥）暴露于拆分后的R-(-)-三唑酮、S-(+)-三唑酮和外消旋三唑酮中，以评估三唑酮的对映体选择性积累情况。单次口服R-(-)-三唑酮、S-(+)-三唑酮和外消旋三唑酮后，发现不同组织中的时间-浓度曲线有所不同。三唑酮对映体能够穿过血脑屏障，大脑是主要的靶器官。24小时后，三唑酮对映体在脂肪中的残留量最高，表明脂肪是主要的蓄积组织。在外消旋三唑酮暴露组中，不同组织中R-(-)-三唑酮的对映体分数表明，R-(-)-三唑酮和S-(+)-三唑酮在吸收和代谢方面存在显著差异，但在排泄和蓄积方面差异变小。从数学模型结果来看，S-(+)-三唑酮的吸收和消除速度比R-(-)-三唑酮快，且R-(-)-三唑酮易于在组织中分布，更容易转化为其代谢产物。此外，在三唑醇的四种对映体中，由S-(+)-三唑酮产生的SR-(-)-三唑醇可能具有最高的杀菌活性和最强的生物毒性，由R-(-)-三唑酮产生的RR-(+)-三唑醇最有可能在石龙子体内生物蓄积。确定SR-(-)-三唑醇和RR-(+)-三唑醇的毒理学效应和剂量-反应关系将有助于全面评估未来使用三唑酮对映体的风险。这些结果丰富和补充了三唑酮对映体环境归宿的知识。
