Design, Synthesis And Biological Activity Of Oxime Ether Derivatives Containing Pyridyl Structur

Since ancient times,agricultural production has been affected and restricted by plant diseases.Plant diseases caused by plant bacteria,fungi,viruses,eggs and other pathogens seriously threaten the safety of agricultural production and bring huge economic losses.With the long-term use of pesticides caused by pathogen resistance problems,environmental pollution and pesticide residues,low efficacy and a series of problems,so it is necessary to create efficient,low toxicity,safe green pesticides,improve the yield and quality of crops.In this paper,a series of new oxime ether derivatives containing pyridine structure were synthesized by taking the pyridine ring as the lead structure and introducing oxime ether groups according to the heterocyclic electron row as the bridge bond.Their structure was characterized by nuclear magnetic resonance technology and their biological activities were investigated.The biological activity of the target compound against tobacco mosaic virus（TMV）was tested by the blight method.The experimental results showed that the optimal therapeutic activity of compound A17 was 60.0%,showing the optimal therapeutic activity.Its EC₅₀ value of 210.8μg/m L was better than that of ribavirin（565.3μg/m L）and Ningnanmycin（255.6μg/mL）.The anti-bacterial activity of A series of compounds against bacterial pathogen:Xanthomonas oryzae pv.Oryzae,Xanthomonas axonopodis pv.Citri and Pseudomonas syringae pv.Actinidiae.The test results showed that some of the target compounds showed good inhibitory activity against rice bacterial blister（Xoo）.The EC₅₀ value of compound A25 against Xoo was 4.6μg/m L,and its biological activity was better than that of the commercial control agent phylloquazole(EC₅₀ value was 33.9μg/m L).At the same time,the mycelial growth rate method was used to study the inhibitory activity of A at a concentration of 50μg/m L against Verticillium dahlia,Fusarium oxysporum,Sclerotinia sclerotiorum,Gibberella zeae,Botryosphaeria dothidea and Thanatephorus cucumeris.The results showed that these compounds had some antifungal activity.Especially at 50μg/m L,compounds A1,A3,A4,A21,A22 and A29 was 91.3%,71.1%,74.6%,91.9%,56.2%and 55.2%,respectively which were better than the control drug Azoxystrobin 76.9%。In addition,the target compound A17 with the best anti-TMV therapeutic activity was selected to further study its mechanism of action.The results of microscale thermophoresis,molecular docking experiments,and morphological observation of the virus showed that the target compound could combine with the shell protein of TMV to a certain extent,thus reducing the activity of the virus.