Synthesis and Herbicidal Activity of Triketone–Quinoline Hybrids as Novel 4‑Hydroxyphenylpyruvate Dioxygenase Inhibitors
journal contributionposted on 2015-06-17, 00:00 authored by Da-Wei Wang, Hong-Yan Lin, Run-Jie Cao, Tao Chen, Feng-Xu Wu, Ge-Fei Hao, Qiong Chen, Wen-Chao Yang, Guang-Fu Yang
4-Hydroxyphenylpyruvate dioxygenase (EC 220.127.116.11, HPPD) is one of the most important targets for herbicide discovery. In the search for new HPPD inhibitors with novel scaffolds, triketone–quinoline hybrids were designed and subsequently optimized on the basis of the structure–activity relationship (SAR) studies. Most of the synthesized compounds displayed potent inhibition of Arabidopsis thaliana HPPD (AtHPPD), and some of them exhibited broad-spectrum and promising herbicidal activity at the rate of 150 g ai/ha by postemergence application. Most promisingly, compound III-l, 3-hydroxy-2-(2-methoxy-7-(methylthio)quinoline-3-carbonyl)cyclohex-2-enone (Ki = 0.009 μM, AtHPPD), had broader spectrum of weed control than mesotrione. Furthermore, compound III-l was much safer to maize at the rate of 150 g ai/ha than mesotrione, demonstrating its great potential as herbicide for weed control in maize fields. Therefore, triketone–quinoline hybrids may serve as new lead structures for novel herbicide discovery.