Design,Synthesis And Herbicidal Activity Of Triketone And Indole-3-acetic Acid Derivatives

Herbicide is an important part of pesticides, and it is the guarantee for control the growth of weeds in the field and the stable production of grain crop. With chemical weed control dominate in agriculture, herbicide selectivity, environmental pollution,the increased resistance and other issues have become increasingly prominent. Therefore, it is importantto ensure the world's food production that new herbicides with low toxicity,high-performance and environmental-friendliness are developed. According to relevant reports, the proherbicides have many advantages compared with the active ingredients,including high selectivity and stability, and the auxin-type herbicides have the advantages of high selectivity, low resistance and so on. In this paper, a series of novel triketone-type derivatives and a series of novel indole-3-acetic acid derivatives were synthesized and further bioe-valuated, and through the results of herbicidal activity preliminary evaluate the triketone-type derivatives whether has the characteristics of proherbicide. The main contents in this paper include the following four parts:1. The research progress of the triketone compounds and auxin herbicides were roughly outlined. In addition, a brief review of the proherbicides was made. Based on this knowledge, the project design ideas were put forward finally.2. A series of novel triketone-type derivatives were designed and synthesized based sulcotrione or mesotrione as active ingredient and the selection of a cleavable group. To use 2-substituents-4-methylsulfonyl benzoic acid as raw material, through multiple steps reactions get the target compounds 3-(N-monosubstituted amine)-2-(2-substituents-4-methylsulfonylbenzoyl) cyclohex-2-enone and 3-(phenyl sulfide)-2-(2-substituted-4-methylsulfonylbenzoy)-cyclohex-2-enone compounds. All the target compounds were confirmed by 1H NMR, 13C NMR, FTIR and HRMS.3. A series of novel a-substituted indole-3-acetic acid derivatives and 3,3-di(1H-indol-3-yl) propanoic acid derivatives were designed and synthesized, using a structure-based drug design approach. And all the target compounds were confirmed by 1H NMR, 13C NMR, FTIR,MS and elemental analysis. According to relevant reports,the indole-3-acetic acid-type compounds can bind TIR1 receptor to block the formation of the TIR1-IAA—Aux/IAA complex andinhibits the expression of auxin-responsive gene.Molecular docking analysis indicates that the phenyl ring in a-substituted indole-3-acetic acid derivatives would strongly interact with Phe82 and Phe380 and the COOH of target compounds would form hydrogen bond with Arg403 and Ser438 of TIR1 receptor, to use the active pocket of indole-3-acetic acid bind TIR1 receptor.4. The herbicidal activity of the synthesized compounds was assayed by using the method of indoor Petri dish test. The greenhouse bioassay testing indicated that the triketone-type compounds 8a-g showed excellent herbicidal activity against Echinochloa crus-galli and rape with the generation of bleaching symptoms at the dosages of 100 ppm and 10 ppm, respectively. And through the preliminary judgment, we can conclude that the compounds 8a-g have a characteristic of the proherbicide. The selectivity rule of a-substituted indole-3-acetic acid derivatives are similarity with auxin-type herbicides,the damage to dicot plants was significantly greater than the monocot plants. Especially,compounds 15d and 15h possess 96% and 95% inhibition rates for the root of rape at the dosages of 100 ppm and they possess 92% and 93% inhibition rates for the roots of rape at the dosages of 10 ppm, respectively.