A series of aryloxyacetic acid derivatives were designed and synthesized as 4-hydoxyphenylpyruvate dioxygenase (HPPD) inhibitors. Preliminary bioassay results reveal that these derivatives are promising Arabidopsis thaliana HPPD (AtHPPD) inhibitors, in particular compounds I12 (K_i = 0.011 µM) and I23 (K_i = 0.012 µM), which exhibit similar activities to that of mesotrione, a commercial HPPD herbicide (K_i = 0.013 µM). Furthermore, the newly synthesized compounds show significant greenhouse herbicidal activities against tested weeds at dosages of 150 g ai/ha. In particular, II4 exhibited high herbicidal activity for pre-emergence treatment that was slightly better than that of mesotrione. In addition, compound II4 was safe for weed control in maize fields at a rate of 150 g ai/ha, and was identified as the most potent candidate for a novel HPPD inhibitor herbicide. The compounds described herein may provide useful guidance for the design of new HPPD inhibiting herbicides and their modification.

中文翻译：

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HPPD抑制剂芳氧基乙酸衍生物的合成及除草活性

设计并合成了一系列芳氧基乙酸衍生物，作为4-羟基苯基丙酮酸双加氧酶（HPPD）抑制剂。初步的生物测定结果表明，这些衍生物是有前途的拟南芥HPPD（At HPPD）抑制剂，特别是化合物I12（K _i = 0.011 µM）和I23（K _i = 0.012 µM），其活性与市售甲基磺草酮相似。 HPPD除草剂（K _i = 0.013 µM）。此外，新合成的化合物在150 g ai / ha的剂量下对被测杂草显示出显着的温室除草活性。特别是II4在芽前处理中表现出较高的除草活性，略高于甲基磺草酮。此外，化合物II4对于玉米田中150 g ai / ha的杂草防治是安全的，并且被确定为新型HPPD抑制剂除草剂的最有效候选者。本文所述的化合物可为设计新的抑制HPPD的除草剂及其修饰提供有用的指导。