Fenoxaprop-P-ethyl, a phenoxy herbicide of the aryloxy–phenoxy–propionic acid group, had a strong control effect when applied POST to weedy rice in this study, with the effective concentrations of 294 μM and 218 μM of herbicide causing 50% inhibition (IC50) in plant height and fresh weight values, respectively. However, fenoxaprop-P-ethyl caused phytotoxicity in cultivated rice. Isoxadifen-ethyl, a widely used herbicide safener in rice, can decrease the phytotoxicity caused by fenoxaprop-P-ethyl. Owing to the extremely similar morphological features and physiological properties of weedy and cultivated rice, it is not practical to spray isoxadifen-ethyl directly on cultivated rice plants to safen them. Applying the safener directly to cultivated rice seeds may be a practical alternative method. To improve the biological activity of isoxadifen-ethyl seed treatments, novel compounds were designed by splicing other groups, including amines, amino acids, and 2- methoxy-5-nitrophenol sodium salt, to the parental structure of isoxadifen-ethyl. Through hydrolysis, acyl chlorination, acyl amination, and esterification, a series of isoxadifen-ethyl derivatives were synthesized and their structures were determined by mass spectrometry and 1H nuclear magnetic resonance spectroscopy. The biological activities of five of the isoxadifen-ethyl derivatives, which possessed recovery effects similar to isoxadifen-ethyl, were able to relieve herbicide phytotoxicity. In pot experiments, isoxadifen-ethyl showed almost no activity as a seed treatment, while three derivative compounds, when used independently as seed treatments, were able to prevent the damage caused by fenoxaprop-P-ethyl. The results will help to develop a new control method for weedy rice, thereby decreasing production costs and increasing farmers’ incomes. Nomenclature: Fenoxaprop-P-ethyl; isoxadifen-ethyl; rice, Oryza sativa L.

中文翻译：

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异恶草芬-乙基衍生物在控制杂草稻的过程中保护稻米免受苯唑丙胺-P-乙基相关的伤害

Fenoxaprop-P-ethyl 是一种芳氧基-苯氧基-丙酸基团的苯氧基除草剂，在本研究中对杂草稻应用 POST 时具有很强的防除效果，有效浓度为 294 μM 和 218 μM 的除草剂导致 50% 的抑制(IC50) 分别为植物高度和鲜重值。然而，fenoxaprop-P-ethyl 对栽培稻造成植物毒性。Isoxadifen-ethyl是一种在水稻中广泛使用的除草剂安全剂，可以降低苯唑草胺引起的植物毒性。由于杂草稻和栽培稻的形态特征和生理特性极其相似，将异恶草芬直接喷洒在栽培稻植物上以保护它们是不切实际的。将安全剂直接应用于栽培水稻种子可能是一种实用的替代方法。为了提高异恶沙芬-乙基种子处理的生物活性，通过将其他基团（包括胺、氨基酸和 2-甲氧基-5-硝基苯酚钠盐）拼接到异恶沙芬-乙基的母体结构上，设计了新型化合物。通过水解、酰基氯化、酰基胺化和酯化反应合成了一系列异恶唑醚-乙基衍生物，并通过质谱和1H核磁共振光谱对其结构进行了测定。五种异恶草芬-乙基衍生物的生物活性与异恶草芬-乙基具有相似的恢复效果，能够减轻除草剂的药害。在盆栽实验中，异恶草芬-乙基作为种子处理几乎没有活性，而三种衍生化合物，当独立用作种子处理时，能够防止由fenoxaprop-P-ethyl造成的损害。研究结果将有助于开发一种新的水稻杂草防治方法，从而降低生产成本，增加农民收入。命名：Fenoxaprop-P-乙基；异恶草芬-乙基；水稻，Oryza sativa L.