Insecticidal Activity Study And Impurity Identification Of Industrial Streptomyces Avermitilis Waste

Doramectin is a new kind of macrolide antiparasitic veterinary medicine,which can drive away the parasites in cattle,pigs,sheep and other domestic animals safely and efficiently.At present,doramectin has been developed and applied in the market for more than 20 years,and now it is widely used in animal husbandry production.In1975,the original strain of Streptomyces avermitilis,which was used to produce doramectin,was isolated from the soil of Hanoi,ITO City,Shizuoka County,Japan,by the Kitasato University of Japan.It was identified as a new species of Streptomyces by Merck in 1976.After gene transformation and biosynthesis,Streptomyces avermitilis produces doramectin,which has lower clearance rate,longer half-life and higher bioavailability in animals.Therefore,doramectin has become the main economic product.In the industrial production process,although genetically modified Streptomyces avermitilis can increase the production of doramectin,the newly introduced impurities and extensive factory separation and extraction process will not maximize the economic value of doramectin.Therefore,it is very important to extract and isolate the industrial genetically modified residue of Streptomyces avermitilis and verify its biological activity.Based on this,industrialized Streptomyces avermitilis was used as the research object in this experiment to explore the unknown activity of its residue in depth.On the one hand,waste reuse can be achieved to increase the economic value of production,on the other hand,unknown components and their activities in impurities can be explored,which lays a foundation for the future development of biological pesticides.The research results are as follows:1.Taking Bradysia odoriphaga Yang et Zhang as the research object,the insecticidal activity experiments were carried out on the ethyl acetate part,petroleum ether part and n-butanol part of Streptomyces avermitilis residue（abbreviated as Dora residue）which produced doramectin.The activity of each part of Dora residue was compared,and it was determined that the ethyl acetate part of Dora residue had the best insecticidal activity.2.Five compounds with similar structure to doramectin were isolated from the ethyl acetate extraction part of Dora residue.YSYZ-DR2C（DR-IM3）with relatively high content was selected for structural identification,and the molecular formula was finally determined to be C₄₉H₇₂O₁₄.The difference between YSYZ-DR2C and doramectin was only the lack of a methyl group on the 14-Position carbon.YSYZ-DR2C was identified as a new compound by comparing the literature and consulting relevant data.