Design, Synthesis, and Insecticidal Activity of Novel m-Diamide Compounds Containing Sulfur

To find efficient insecticides with novel structures, 16 novel m-diamide compounds containing sulfur were designed and synthesized based on the principle of biologically active factor splicing with cyproflanilide as the lead compound. Preliminary biological assay data showed that some of the target compounds exhibited insecticidal activity above 90% against Mythimna separata at 0.01 mg/L and Aphis craccivora at 100 mg/L, which were better than cyproflanilide. Meanwhile, most compounds still maintain 100% mortality at 1 mg/L for Plutella xylostella. In particular, compounds 5c, 5e, 5f, and 5g revealed excellent activities against P. xylostella, M. separata, and A. craccivora, exhibiting efficient and broad-spectrum insecticidal activity. Additionally, the interaction between the metabolites of cyproflanilide, compound 5g, and γ-aminobutyric acid receptor protein was studied by molecular docking method. The results showed that they could be stably bound to the potential active cavity in the protein to form a protein-ligand complex, thus showing excellent insecticidal activity, which is consistent with the data on the excellent insecticidal activity of compounds. This work showed that sulfur-containing compounds might provide certain clues for structure optimization for the development of new insecticides.