The chirality of pesticides has emerged as an important issue in pesticide design and applications because enantiomers can differ greatly in their environmental fate and risk. Despite the increasing concern over the unintended effects of inactive or less effective enantiomers, massive amounts of chiral pesticides are applied as racemic mixtures. As a potential substitute for glyphosate, the market of glufosinate is expected to grow rapidly. However, very little information is available on its enantioselective efficacy-risk assessment, especially at the environmentally relevant concentration. The overall aim of this study is to determine if the switch from glufosinate racemic mixture to l-glufosinate was favored regarding environmental health. Thus, we examined (i) the herbicidal activity of Rac- and l-glufosinate to the weed, Echinochloa crus-galli, and (ii) adverse effects on nontarget zebrafish (Danio rerio). Significant higher herbicidal activities were achieved by l-glufosinate at both 1 and 5 mg/L. Embryotoxicity and teratogenicity are significantly different: Rac-glufosinate induced a significantly higher lethality (LC₅₀ = 17.29 mg/L) and malformations. The oxidative stress markers, including superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA), were preferably induced by Rac-glufosinate at mRNA and enzymatic activity levels. In summary, we suggest that l-glufosinate should be applied preferably over Rac-glufosinate.

中文翻译：

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评估广泛使用的手性草铵膦的功效风险：从外消旋体转换为单一对映体？

农药的手性已成为农药设计和应用中的重要问题，因为对映异构体的环境命运和风险可能存在很大差异。尽管人们越来越关注无活性或效果较差的对映异构体的意外作用，但仍大量使用了手性农药作为外消旋混合物。草甘膦作为草甘膦的潜在替代品，有望迅速增长。然而，关于其对映选择性功效-风险评估的信息很少，特别是在与环境有关的浓度下。这项研究的总体目标是确定从草铵膦外消旋混合物向1-草铵膦的转换是否有利于环境健康。因此，我们研究了（i）Rac-和杂草中的l-草铵膦，E草（Echinochloa crus-galli）和（ii）对非目标斑马鱼（Danio rerio）的不利影响。1-草铵膦在1 mg / L和5 mg / L时均具有较高的除草活性。胚胎毒性和致畸性明显不同：Rac-草铵膦诱导的致死率（LC ₅₀ = 17.29 mg / L）和畸形明显更高。氧化应激标志物，包括超氧化物歧化酶（SOD），过氧化氢酶（CAT）和丙二醛（MDA），优选由Rac-草铵膦在mRNA和酶活性水平诱导。总之，我们建议升-glufosinate应当超过外消旋-草铵膦优选适用。