Design, Synthesis,\nand Insecticidal Activity of Isoxazoline\nDerivatives Incorporating an Acylhydrazine Moiety

The long-term use of agricultural insecticides has led\nto the development\nof resistant strains. In this context, the isoxazoline structure has\nbecome an active area of pesticide research owing to its wide insecticidal\nspectrum, nontoxicity to mammals, and lack of cross-resistance with\nknown insecticides. In the present study, based on the discovery of\ncompound <b>G22</b> in our previous work, a series of novel\nisoxazoline compounds containing acylhydrazine were designed and synthesized\nusing a scaffold hopping strategy. The insecticidal activities of\nthe target compounds were assessed, and compound <b>L17</b> (LC<sub>50</sub> = 0.489 mg/L) showed insecticidal activity against Spodoptera frugiperda superior to those of the commercial\ninsecticides indoxacarb (LC<sub>50</sub> = 3.14 mg/L) and fluralaner\n(LC<sub>50</sub> = 0.659 mg/L). Theoretical calculations indicated\nthat the introduction of acylhydrazine plays an important role in\nthe biological activity of the target compounds. Furthermore, the\nenzyme-linked immunosorbent assay and molecular docking results indicated\nthat <b>L17</b> may act on the GABA receptor of the target insect.\nThese results indicated that <b>L17</b> is a potential candidate\ncompound for controlling S. frugiperda populations in agriculture.