Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
Departamento de Bioquímica e Biologia Molecular, Viçosa, MG, Brazil.
Pest Manag Sci. 2017 Nov;73(11):2360-2371. doi: 10.1002/ps.4623. Epub 2017 Aug 17.
The photosynthetic apparatus is targeted by various herbicides, including several amides such as diuron and linuron. Considering the need for the discovery of new active ingredients to cope with weed resistance, the synthesis of a series of trifluoromethyl aryl amides is herein described whose inhibitory properties were assessed in vitro on the photosynthetic electron transport chain, and in vivo on the growth of a model cyanobacterial strain. Theoretical studies were also carried out.
Starting with 1-fluoro-2-nitro-4-(trifluoromethyl) benzene, the preparation of the amides was achieved via a three-step sequence, namely nucleophilic aromatic substitution, reduction with SnCl /HCl, and acylation reactions. The measurement of ferricyanide reduction by functionally intact spinach chloroplasts showed that several derivatives are capable of inhibiting the photosynthetic apparatus. The most active amides presented IC values close to 1 μmol L , and showed the presence of a 4-bromophenyl group as a common structural feature. The addition of these brominated amides to the culture medium of a model cyanobacterial strain, Synechococcus elongatus PCC 6301, caused various degrees of growth inhibition. Theoretical studies (molecular modeling and quantitative structure-activity relationship) of all amides and their comparison with some known herbicides confirmed these experimental findings and provided more in-depth information about the possible molecular target of these compounds.
Trifluoromethyl amides herein described, which were shown to act at the PSII level, may represent a novel scaffold to be exploited aiming at the development of new active ingredients for weed control. © 2017 Society of Chemical Industry.
光合作用装置是各种除草剂的靶标，包括几种酰胺类除草剂，如敌草隆和利谷隆。考虑到需要发现新的有效成分来应对杂草抗性，本文描述了一系列三氟甲基芳酰胺的合成，其抑制特性在体外对光合作用电子传递链进行了评估，并在模型蓝藻菌株的生长中进行了体内评估。还进行了理论研究。
从 1-氟-2-硝基-4-(三氟甲基)苯开始，通过三步序列实现酰胺的制备，即亲核芳香取代、SnCl 2 /HCl 还原和酰化反应。功能完整的菠菜叶绿体中铁氰化物还原的测量表明，几种衍生物能够抑制光合作用装置。最有效的酰胺的 IC 值接近 1 μmol L -1 ，并显示出 4-溴苯基基团的存在作为共同的结构特征。将这些溴化酰胺添加到模型蓝藻菌株 Synechococcus elongatus PCC 6301 的培养基中，引起不同程度的生长抑制。所有酰胺的理论研究（分子建模和定量构效关系）及其与一些已知除草剂的比较证实了这些实验结果，并提供了有关这些化合物可能的分子靶标的更深入信息。
本文描述的三氟甲基酰胺，其作用于 PSII 水平，可能代表一种新的骨架，可用于开发用于杂草控制的新有效成分。© 2017 化学工业协会。
