Study on the structural modification and insecticidal activity of a new biological pesticide-spinetoram

Spinosad and spinetoram, as commercially available spinosyns products, which is a novel class of highly effective biological insecticides, demonstrate high insecticidal potency, rapid degradation rates, environmental compatibility, and low toxicity to non-target organisms. In order to identify more effective insecticides, this study utilized spinetoram J as the lead compound and introduced pyridine rings with various substituents to synthesize a series of spinetoram derivatives. The structures of spinetoram derivatives were confirmed by ¹H NMR, ¹³C NMR and HRMS, and the insecticidal activity of derivatives against Thrips Palmi Karny and Acyrthosiphon Pisum was determined. The results showed that newly synthesized derivatives demonstrated good insecticidal activity against Thrips Palmi Karny and Acyrthosiphon Pisum, with some derivatives exhibiting superior efficacy compared to spinosad and spinetoram. A preliminary analysis of the structure-activity relationship of spinetoram derivatives revealed that the incorporation of active groups containing electron-withdrawing substituents (notably chlorine, fluorine, trifluoromethyl, etc.) was more likely to produce spinetoram derivatives with high insecticidal activity. This finding holds considerable importance for future research focused on the derivatization of spinetoram.