| Matrine is a kind of monomer alkaloid extracted from Sophora flavescens,which has a wide range of pharmacological activities,such as anti-tumor,anti-inflammatory,antiviral,bacteriostatic,insecticidal and so on.Matrine is a widely used natural plant pesticide in agricultural application.It has the characteristics of specificity and naturalness.It will not pollute the environment and agricultural products,and will be relatively safe to people and livestock,which will not kill the corresponding pests directly and completely,but the control of the biological population of pests will not seriously affect the production and reproduction of the plant population.It shows that Matrine is very green and environmentally friendly from the chemical pesticides with high toxicity and high residue.However,Matrine has some shortcomings,such as low bioavailability,weak single activity,toxic and side effects on the central nervous system.Therefore,it is of great significance to modify and modify the structure of Sophora flavescens,a botanical pesticide.In order to enhance its insecticidal activity,70 oximine derivatives were designed and synthesized with Matrine as the lead compound.In the first route,Matrine oxime was synthesized by the reaction of Matrine with tert-butyl nitrate,and a series of oximine derivatives were synthesized by introducing oxime ester and oxime ether group.Route 2activated the carbon-oxygen double bond of Matrine amide,and then formed a stable imine structure with arylprimary amine to obtain a series of Matrine aromatic imine derivatives.The reaction conditions of the two routes are mild,the operation is simple,and the yield is high.The structure of the synthesized target compound was characterized and confirmed by nuclear magnetic resonance hydrogen spectroscopy,carbon spectrum and mass spectrum.The reaction conditions of Matrine oxamic ether derivatives were optimized by orthogonal experiment,and the yield was increased to 65%.Three common pests,red fire ant,cowpea thrips and Drosophila melanogaster,were selected to test the insecticidal activity of the synthesized target compounds in vitro.Among Oxime ester compounds,A7,A8,A10,A13 had higher stomach toxicity activity to red fire ant than Matrine,and most of the compounds had higher stomach toxicity activity to cowpea thrips than Matrine,among which A1 and A4 had higher contact activity to red fire ant than Matrine.The gastric toxicity activity of oximes to red fire ants and cowpea thrips was significantly higher than that of Matrine,and B1 and B14 activities were higher than those of avermectin,which was similar to that of avermectin.Most oxime ethers have higher water solubility and higher contact activity against red fire ants than Matrine.The stomach toxicity activity of C 20 and C 21 to red fire ants was slightly higher than that of Matrine. |
