Background: Anthranilic diamide insecticides control lepidopteran pests through selectively binding and activating insect ryanodine receptors. In order to search for potential insecticides targeting the ryanodine receptors, a series of anthranilic diamide analogs including trifluoromethyl, nitro, or chloro groups were designed and synthesized by the principle of bioisosterism and structural optimization.
Results: Insecticidal data indicated that some compounds displayed good activity against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella). In particular, the larvicidal activity of 6p against P. xylostella was 95% at 0.01 mg L-1 , equivalent to chlorantraniliprole (85%, 0.01 mg L-1 ). The comparative molecular similarity index analysis model obtained indicated that hydrogen bond acceptor and electron-withdrawing groups in the R'3 group are favourable for insecticidal activity against M. separata, which is consistent with the structure-activity relationships. Moreover, the calcium imaging experiment indicated, like chlorantraniliprole, that 6h and 6p are interacting with the ryanodine receptor.
Conclusion: Introducing trifluoromethyl, nitro, or chloro groups to a specific position in the N-phenylpyrazole could improve or maintain the activity against M. separata and P. xylostella. 6h and 6p could be used as potential lead compounds for ryanodine receptor modulators. © 2018 Society of Chemical Industry.
Keywords: CoMSIA model; N-substituted phenylpyrazole; calcium channel; insecticidal activity.
© 2018 Society of Chemical Industry.