Nornicotine-typed insecticides: The potential insecticides with strong activity against Diaphorina citri

Abstract

Nicotine and nornicotine-typed compounds are well-known for its potential as insecticide. Some researches have shown that nicotine was highly toxic to Diaphorina citri Kuwayama, an invasive and fast spreading pest. Here we report the effects of nornicotine-typed insecticide against D. citri. Novel compounds A1-A8, B1–B28, C1–C18 and D1-D12 were synthesized by reported procedure. And bioassays indicated that some of these compounds exhibited good effects against D. citri. Compounds B2, B3, B8, B12, B13, B22, C5, C7, D5, and D9 exhibited the mortality up to 100% within 120 h in 50 mg/L. And further data shows that A2-5, A7, B1, B8, B20 and B22 showed rapid insecticidal activities against D. citri in 24 h with the low LC₅₀ (LC₅₀ < 50 mg/L in 24 h, and LC₅₀ < 30 mg/L in 72 h). Nornicotine-typed derivatives exhibited activity against D. citri, and B8 and B22 exhibited the best insecticidal activity with an LC₅₀ of 18.0 ± 1.0, 18.2 ± 0.9 mg/L in 24 h, which had the lower cost than nicotine and showed the potential as powerful insecticides.