Abstract
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 (Ki = 0.011 µM) and I23 (Ki = 0.012 µM), which exhibit similar activities to that of mesotrione, a commercial HPPD herbicide (Ki = 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.
Highlights
N Scheme 1 [2,3,4,5,6]
Phytoene is accumulated when the transformation of hydroxyphenylpyruvic acid (HPPA) to homogentisic acid (HGA) is interfered with an hydoxyphenylpyruvate dioxygenase (HPPD) inhibitor [9,10]; plants become severely damage when exposed to sunlight, resulting in bleaching symptoms followed by necrosis and death [11,12]
The results show that the chloro-substituted pyridine exhibited superior herbicidal activity, which provides a theoretical basis for the further development of highly effective HPPD herbicides
Summary
N Scheme 1 [2,3,4,5,6]. The HPPD amino acid sequence homologies in plants and mammals are significantly different [7,8], and this difference affects the binding stability between an inhibitor and HPPD, leading to inhibitor activities that differ among various species and genera and providing a theoretical basis for the design of inhibitors that are highly selective and safe [2]. These derivatives were subjected to HPPD inhibition, herbicidal activity, crop safety and structure–activity relationship (SAR) studies.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
