Protoporphyrinogen oxidase (PPO) is an important target for discovering new herbicides that interfere with the synthesis of porphyrin. To discover new PPO inhibitors with improved biological activity, a series of new diphenyl ethers containing tetrahydrophthalimide were designed and synthesized. Among them, J6.1 (IC50 = 4.7 nM) and J6.3 (IC50 = 30.0 nM) show higher maize (Zea mays L.) PPO inhibitory activity than the commercial herbicides oxyfluorfen (IC50 = 117.9 nM) and flumioxazin (IC50 = 157.1 nM). The greenhouse herbicidal activity of J6.3 is comparable to that of oxyfluorfen, and it is greater than that of flumioxazin. Even at a dose of 300 g ai ha−1, cotton (Gossypium hirsutum L.) and peanut (Arachis hypogaea L.) show greater tolerance to J6.3, suggesting that J6.3 could be used for further development of new herbicide candidates in those fields. In addition, molecular docking has been used to further study the mechanism of action of J6.3. The results show that the introduction of a nitro group and tetrahydrophthalimide into the diphenyl ether structure is beneficial to biological activity.

中文翻译：

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新型PPO抑制剂的除草活性及分子对接研究

原卟啉原氧化酶（PPO）是发现干扰卟啉合成的新除草剂的重要靶点。为发现具有更高生物活性的新型PPO抑制剂，设计合成了一系列含有四氢邻苯二甲酰亚胺的新型二苯醚。其中，J6.1（IC50= 4.7 nM) 和 J6.3 (IC50= 30.0 nM) 显示更高的玉米 (玉米L.) PPO抑制活性优于市售除草剂氧氟草醚（IC50= 117.9 nM) 和氟咪嗪 (IC50= 157.1 纳米）。J6.3的温室除草活性与氧氟草醚相当，大于氟嘧啶。即使剂量为 300 g ai ha-1， 棉 （陆地棉L.) 和花生 (花生L.) 对 J6.3 表现出更大的耐受性，表明 J6.3 可用于在这些领域进一步开发新的候选除草剂。此外，分子对接已被用于进一步研究J6.3的作用机制。结果表明，在二苯醚结构中引入硝基和四氢邻苯二甲酰亚胺有利于生物活性。