秦艽根对小菜蛾杀虫活性物质初选

Preliminary Study on the Insecticidal Active Substances in the Roots of Gentiana macrophylla against Plutella xylostella

[目的]研究秦艽根对小菜蛾的杀虫活性物质。[方法]以乙醇超声法提取秦艽根中的活性物质,采用浸虫法测试提取物对小菜蛾的触杀活性;并采用液-液分配萃取法用石油醚、氯仿、乙酸乙酯、正丁醇对提取物依次萃取,且跟踪测试各萃取物的活性。[结果]秦艽根提取物对小菜蛾3龄幼虫的LC50为0.795 8 g/ml;提取物分离后石油醚萃取物活性最强,氯仿萃取物、乙酸乙酯萃取物次之,而正丁醇萃取物及水层剩余物作用不明显。[结论]秦艽根对小菜蛾具有较强的触杀活性且杀虫活性物质为脂溶性的化合物。

[ Objective] The research aimed to study the insecticidal active substances in the roots of Gentiana macrophylla against Plwtella xylostella. [ Method] The active substances in the roots of G. macrophylla were extracted by ethanol ultrasonic method. The contact activity of the extracts against P. xylostella was tested by using insect-dipping method. The extracts were leached with petroleum ether, chloroform, ethyl acetate and n-butanol by using liquid - liquid allocation extraction method in order. The tracking test was made on the activity of each extract. [Result] LC50 of the extract from the roots of P. xylostella to the 3^rd-instar larva was 0.795 8 g/ml. The activity of petroleum ether extract was strongest after separating the extracts, followed by chloroform extract and ethyl acetate extract. But the effects of n-butanol extract and remainder in water layer were not obvious. [ Conclusion] The roots of G. macrophylla had stronger contact activity against P. xylostella and the insecticidal active substances were liposoluble compounds.