Synthesis Of Capsaicin Analogs And Activities Insecticide And Herbicide

China has the largest population than other countries on over the world.Maintaining high and stable cereals yield is one of the important foundations for maintaining social stability in China.In China,the process of planting to harvesting of crops,plant diseases,pests,and weeds are always accompanied by them.There are many ways to wipe out pests in agriculture,spraying pesticides is still the most effective way to control pests at present.However,the widespread use of pesticides has led to many problems.For example,the increasing resistance of pests,severe pesticide residues,and excessive harm to non-target life.Therefore,the discovery of efficient,green and safe novel lead compounds is the most important task in the development of new pesticides.Capsaicin and its derivatives have multiple biological activities.It is widely used in many different fields such as agriculture,medicine and industry.Our research group designed and synthesized 234 known compounds.The structure of all compounds was determined by ~1H NMR.The insecticidal activity and herbicidal activity of the synthesized capsaicin analogues have not been reported in the literature.The title compounds were evaluated for insecticidal and herbicidal activity.We analyze experimental results and finally determine the structure-activity relationship.The main research results are as follows:Chemical synthesis:We designed and synthesized 234 compounds through N-acylation,which are based on benzylamine,2-fluorobenzylamine,3-fluorobenzylamine,4-fluorobenzylamine,2,4-difluorobenzylamine,2,6-Difluorobenzylamine,vanillinamine hydrochloride,2-thiophenecarboxylic acid,2-furancarboxylic acid,2-(trichloroacetyl)pyrrole as raw materials.Through N-acylation reaction,234 compounds were designed and synthesized.The structures of all compounds were confirmed by ~1H NMR.Determination of insecticidal activity:Using third instar larvae of Mythimna seperata as test insects.Capsaicin and permethrin as positive controls.Acetone as blank controls,the insecticidal activity of title compounds were evaluated.Using the leaf dish method,at a dose of 4?g/piece,after 48 hours of feeding.The lethal rates of compounds A30 were 13%.Compared with the positive control capsaicin(4?g/piece,0%),Which is still a gigantic difference compared with commercial permethrin(4?g/piece,100%).Determination of herbicidal activity:The test plants are Echinochloa crusgalli,Portulaca oleracea,Abutilon theophrasti.Isoxaflutole and capsaicin as positive control agents.DMSO as blank control.The herbicidal activity of title compounds were evaluated by Using the small cup method,at a concentration of 0.1mg/m L.The results showed some compounds exhibited both growth inhibitory effects and better albinism on Echinochloa crusgall and Portulaca oleracea.At a concentration of 0.01mg/m L,compounds A27 and F27 showed significant albinism.The E.crusgalli and A.theophrasti were treated with soil treatment and stem-leaf spraying method.At a dosage of 150g/hm~2,A27 and F27 showed certain herbicidal activity.At the tested concentrations,capsaicin showed no herbicidal activity.The three determination methods show that the title compound still has a certain gap compared with the commercial Isoxaflutole.