To seek novel and safe protoporphyrinogen oxidase (PPO, EC 1.3.3.4) inhibitors with excellent herbicidal activity. A series of novel phenoxypyridine derivatives containing natural product coumarins with allelopathy were designed and synthesized based on bioisosterism and active subunit combination in this research. Compounds W3.1 and W3.4, with the half-maximal inhibitory concentration (IC₅₀) value of 0.02653 mg/L and 0.01937 mg/L, respectively, displayed excellent herbicidal activity in greenhouse. Their herbicidal activity was similar to commercial herbicide oxyfluorfen (IC₅₀ = 0.04943 mg/L). The best field inhibitory effect of compounds W3.1 and W3.4 recorded was at doses of 450 g ai/ha and 300 g ai/ha, respectively. Compound W3.4 had the best herbicidal activity among all the target compounds in this paper. Molecular docking analysis revealed that compounds W3.1 and W3.4 could form a hydrogen bonds with the amino acid AGR-98 and a π-π superposition with the amino acid PHE-398, respectively, which was similar to the oxyfluorfen. The crop selectivity tests results indicated that maize, cotton and soybean showed high tolerance to compound W3.4. Compound W3.4 reduced the C_a and C_b contents of wheat and rice, but had less effect on maize, cotton and soybean. Selectivity of compound W3.4 in maize, cotton and soybean were appeared to be due to reduced absorption of the herbicide compared to wheat and rice. Compound W3.4 deserves further attention as a candidate structure for new herbicides.

寻找具有优异除草活性的新型安全原卟啉原氧化酶（PPO，EC 1.3.3.4）抑制剂。本研究基于生物等排和活性亚基组合，设计合成了一系列具有化感作用的天然产物香豆素苯氧吡啶衍生物。化合物W3.1和W3.4的半数最大抑菌浓度(IC ₅₀ )分别为0.02653 mg/L和0.01937 mg/L，在温室中表现出优异的除草活性。它们的除草活性类似于商业除草剂氧氟草 醚(IC ₅₀ = 0.04943 mg/L)。化合物W3.1和W3.4的最佳场抑制效果记录的剂量分别为 450 克活性成分/公顷和 300 克活性成分/公顷。在本文所有目标化合物中，化合物W3.4的除草活性最好。分子对接分析表明，化合物W3.1和W3.4可以分别与氨基酸AGR-98形成氢键，与氨基酸PHE-398形成π-π叠加，与氧氟草醚相似。作物选择性试验结果表明，玉米、棉花和大豆对化合物W3.4表现出较高的耐受性。化合物W3.4降低了C _a和C _b小麦和水稻的含量，但对玉米、棉花和大豆的影响较小。与小麦和水稻相比，化合物W3.4在玉米、棉花和大豆中的选择性似乎是由于除草剂的吸收减少。化合物W3.4作为新型除草剂的候选结构值得进一步关注。