Syntheses and Herbicidal Activity of Triketone-Quinoline Hybrid as Novel 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors

To search for new HPPD inhibitors with novel scaffolds, triketone-quinoline hybrids were designed and subsequently optimized based on 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 post-emergence application. Most promisingly, compound III-l, 3-hydroxy-2-(2-methoxy-7-(methylthio) -quinoline-3-carbonyl)cyclohex-2-enone (Ki = 0.009 M, 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 field. Therefore, triketone-quinoline hybrid may serve as a new lead structure for novel herbicides discovery.

Website: http://www.arjonline.org/agricultural-sciences/american-research-journal-of-agriculture/