Synthesis and Insecticidal Activities of Novel Anthranilic Diamides Containing Acylthiourea and Acylurea

Two series of anthranilic diamides containing acylthiourea and acylurea linkers were designed and synthesized, with changed length and flexibility of the linkers to compare to known anthranilic diamide insecticides. In total, 26 novel compounds were synthesized, and all compounds were characterized by (1)H nuclear magnetic resonance and high-resolution mass spectrometry. Their insecticidal activities against oriental armyworm (Mythimna separata), mosquito larvae (Culex pipiens pallens), and diamondback moth (Plutella xylostella) were evaluated. The larvicidal activities against oriental armyworm indicated that the introduction of acylthiourea into some structures could retain their insecticidal activity; 8 of the 15 compounds (13a-13e, 14a-14e, and 15a-15e) exhibited 100% larvicidal activity at 10 mg/L. However, the introduction of acylurea decreased the insecticidal activity; only 3 of the 11 compounds (17a-17k) exhibited 100% larvicidal activity at 200 mg/L. The whole-cell patch-clamp technique indicated that compound 13b and chlorantraniliprole exhibited similar effects on the voltage-gated calcium channel. The calcium-imaging technique was also applied to investigate the effects of compounds 13b and 15a on the intracellular calcium ion concentration ([Ca(2+)](i)), which indicated that they released stored calcium ions from endoplasmic reticulum. Experimental results denoted that several new compounds are potential activators of the insect ryanodine receptor (RyR).