Synthesis and herbicidal activity of aryloxyacetic acid derivatives as HPPD inhibitors

Abstract

A series of aryloxyacetic acid derivatives were designed and synthesized as HPPD inhibitors. The preliminary bioassay results indicated that these derivatives displayed promising Arabidopsis thaliana HPPD (AtHPPD) inhibitory activity, such as compound I12 (K i = 0.011 µM) and compound I23 (K i = 0.012 µM), which were similar with commercial HPPD herbicide Mesotrione (K i = 0.013 µM). Furthermore, the newly synthesized compounds showed significant greenhouse herbicidal activities against tested weeds at dosages of 150 g ai/ha. In particular, compound II4 exhibited highly herbicidal activity for pre-emergence treatment, even better than those of Mesotrione. Besides, compound II4 was safe for weed control in maize fields at the rate of 150 g ai/ha. Therefore, compound II4 was identified as the most potent candidate for novel HPPD inhibitor herbicide. Compounds described herein might provide useful ideas in the design and modification of new HPPD inhibiting-based herbicides.