Hai-Lian Wang,Hao-Ran Li,Yi-Chi Zhang,Wen-Tao Yang,Zheng Yao,Ren-Jun Wu,Cong-Wei Niu,Yong-Hong Li,Jian-Guo Wang
In the present study, we have designed and synthesized a series of 42 novel sulfonylurea compounds with ortho-alkoxy substitutions at the phenyl ring and evaluated their herbicidal activities. Some target compounds showed excellent herbicidal activity against monocotyledon weed species. When applied at 7.5 g ha–1, 6–11 exhibited more potent herbicidal activity against barnyard grass (Echinochloa crus-galli) and crab grass (Digitaria sanguinalis) than commercial acetohydroxyacid synthase (AHAS; EC 2.2.1.6) inhibitors triasulfuron, penoxsulam, and nicosulfuron at both pre-emergence and postemergence conditions. 6–11 was safe for peanut for postemergence application at this ultralow dosage, suggesting that it could be considered a potential herbicide candidate for peanut fields. Although 6–11 and triasulfuron share similar chemical structures and have close Ki values for plant AHAS, a significant difference has been observed between their LUMO maps from DFT calculations, which might be a possible factor that leads to their different behaviors toward monocotyledon weed species.
Ke-Jian Li,Ren-Yu Qu,Yu-Chao Liu,Jing-Fang Yang,Ponnam Devendar,Qiong Chen,Cong-Wei Niu,Zhen Xi,Guang-Fu Yang
The issue of weed resistance to acetohydroxyacid synthase (EC 2.2.1.6, AHAS) inhibitors has become one of the largest obstacles for the application of this class of herbicides. In a continuing effort to discover novel AHAS inhibitors to overcome weed resistance, a series of pyrimidine–biphenyl hybrids (4aa–bb and 5aa–ah) were designed and synthesized via a scaffold hopping strategy. Among these derivatives, compounds 4aa (Ki = 0.09 μM) and 4bb (Ki = 0.02 μM) displayed higher inhibitory activities against Arabidopsis thaliana AHAS than those of the controls bispyribac (Ki = 0.54 μM) and flumetsulam (Ki = 0.38 μM). Remarkably, compounds 4aa, 4bb, 5ah, and 5ag exhibited excellent postemergence herbicidal activity and a broad spectrum of weed control at application rates of 37.5–150 g of active ingredient (ai)/ha. Furthermore, 4aa and 4bb showed higher herbicidal activity against AHAS inhibitor-resistant Descurainia sophia, Ammannia arenaria, and the corresponding sensitive weeds than that of bispyribac at 0.94–0.235 g ai/ha. Therefore, the pyrimidine–biphenyl motif and lead compounds 4aa and 4bb have great potential for the discovery of novel AHAS inhibitors to combat AHAS-inhibiting herbicide-resistant weeds.
危险品化学品经营许可证（带存储）