关键词: 植物杀虫剂, 生物活性, NADH泛醌氧化还原酶抑制剂

Abstract: One of the most efficient ways to obtain compounds with insecticide properties from traditional insecticidal plants is the extraction and isolation of minor secondary metabolites. Elliptone, isolated from the roots of Derris elliptica, is an active insecticide in the same chemical family as rotenone. Differences in toxicity, antifeedancy, inhibition of growth and development, and oviposition deterrence between elliptone and rotenone were evaluated with respect to imported cabbage worm (Pieris rapae), diamondback moth (Plutella xylostella), cabbage aphid(Brevicoryne brassicae), striped flea beetle (Phyllotreta vittata), and citrus red mite(Panonychus citri). The results showed that the toxicity of elliptone varied between species. Elliptone exhibited strong toxicity against citrus red mite, diamondback moth larvae, and adults of the striped flea beetle, but significantly lower toxicity against cabbage aphid and imported cabbage worm compared to rotenone (based on comparison of LC₅₀). Both elliptone and roteone displayed remarkable antifeedant activity. Elliptone, and to a lesser extent, rotenone, had some inhibitory effect on growth and development and deterred oviposition. Elliptone had a lesser inhibitory effect on NADHubiquinone oxidoreductase activity (50% inhibition ［IC₅₀］ at 5.27 nmol·mL-1) compared to rotenone (IC₅₀ at 2.58 nmol·mL^-1) which suggests that is a less effective respiratory inhibitor than the latter. Based on the data obtained in this investigation, it is possible that the higher toxicity of elliptone in leaf-disc immersion trials reflects its lower antifeedant activity and consequently higher ingestion rate.

Key words: botanical insecticides, bioactivity, NADHubiquinone oxidoreductase inhibition