苍耳倍半萜内酯和博落回生物碱对三种蔬菜害虫的活性比较

为探讨苍耳（Xanthium sibiricum）倍半萜内酯分离物L-Ⅱ (主要成分为4β,5β-环氧苍耳素-1α,4α-内过氧化物) 的活性大小，将其与博落回（Macleaya cordata）总生物碱提取物MacSC （主要成分为血根碱和白屈菜红碱）的活性进行了比较研究。结果显示，两种测试物对试虫均表现较高活性，其中，苍耳倍半萜内酯分离物L-Ⅱ对小菜蛾（Plutella xylostella ）4龄幼虫的选择性拒食中浓度（AFC₅₀）为23.6 mg/L，活性强于博落回生物碱提取物MacSC（111.8 mg/L）；在测试浓度为10 mg/mL时，L-Ⅱ处理组的小菜蛾4龄幼虫仅有4.30%发育为成虫，是对照的6.12%，小菜蛾蛹的羽化率为对照的12.05%，而MacSC的影响相对较低，两值分别为对照的33.89%和56.23%； 在上述测试浓度，L-Ⅱ对桃蚜 （Myzus persicae）和萝卜蚜（Lipaphis erysimi）均有较强的忌避作用，24 h忌避率分别为72.03%和74.47%，而MacSC对桃蚜的忌较效果较低（55.50%），对萝卜蚜无忌避活性。说明苍耳倍半萜内酯分离物L-Ⅱ对几种试虫的拒食、忌避和生长发育抑制活性均高于博落回总生物碱提取物MacSC。

Comparative activity of sesquiterpene mactones from Xanthium sibiricum and alkaloids from Macleaya cordata against insect pests

The comparative activity of sesquiterpene lactones from Xanthium sibiricum, the main active ingredient L-Ⅱ of which was 4β,5β-epoxyxanthatin-1α,4α-endoperoxide, and alkaloids from Macleaya cordata (MacSC), main active ingredients of which was sanguinarine and chelerythrine, against three insect pests, including diamondback moth Plutella xylostella (Lepidoptera: Plutellidae), peach aphid Myzus persicae (Hemiptera: Aphididae) and mustard aphid Lipaphis erysimi (Hemiptera: Aphididae), were studied in laboratory. The results showed that the two tested plants materials possessed high antifeedant, deterrent and development inhibiting activities. The AFC₅₀ (antifeeding median concentration) values of L-Ⅱ and MacSC against P. xylostella were 23.6 mg/L and 111.8 mg/L, respectively, in choice bioassay. Meanwhile, they also had pupation and eclosion inhibiting activities against P. xylostella, with only 4.30% larvae developing into adults for L-Ⅱ and 23.80% for MacSC, when the tested concentration was 10 mg/mL. However, L -Ⅱ had deterrent effects on M. persicae and L. erysimi, with choice deterrent rate as 72.03% and 74.47%, respectively, but MacSC had lower deterrent effect on M. persicae and no deterrent effect on L. erysimi. These findings suggested that the sesquiterpene lactones from Xanthium sibiricum have stronger antifeedant, deterrent and development inhibiting effects than alkaloids from Macleaya cordata on the insects tested.