Design, synthesis and biological activities of novel anthranilic diamides containing dihydroisoxazoline and isoxazole

Anthranilic diamides are one of the most important classes of modern agrochemical insecticides. To discover new structures with higher activity, lower toxicity and lower residue, a series of novel anthranilic diamides containing dihydroisoxazoline and isoxazole was designed and synthesized. Their structures were characterized by means of melting points, proton nuclear magnetic resonance(1H NMR), 13C NMR and high resolution mass spectrometry(HRMS). According to the bioassay data, it was found that some of the title compounds exhibit moderate insecticidal activity and good antifungal activity. In particularly, compound 15b with a concentration of 50 mg/L shows a lethality rate of 60.0% against Mythimna separata Walker and a lethality rate of 50.0% against Culex pipiens pallens with a concentration of 1 mg/L. Moreover, compound 15b showed good antifungal activities(58.8%, 77.1%, 70.7%, 55.3%, 60.7%, 65.4%) when against all the tested fungi(Cercospora arachidicola Hori, Physalospora piricola, Rhizoctonia cerealis, Bipolaris maydis, Watermelon anthracnose, Fusarium moniliforme). The effects of compounds 14h, 14j and 15b on the concentration of intracellular calcium ion([Ca2+]i) in the central neurons of Mythimna separate Walker were well investigated via calcium imaging technique. The results demonstrate that the novel compounds can elevate the calcium concentration in the neurons, denoting that some new structures are potential modulators of the insect ryanodine receptor(RyR).