从天然产物到新农药创制——杀虫植物苦皮藤研究进展

天然产物是新农药创制的重要资源。苦皮藤(Celastrus angulatus)是一种传统杀虫植物,广泛分布于我国长江和黄河流域的丘陵浅山地区。1980年以来作者对苦皮藤进行系统的研究,获得下列重要成果:(1)从苦皮藤根皮和叶子的提取物中分离、鉴定出54个化合物,其中37个为新化合物,这些化合物都属于倍半萜多元醇酯,具有二氢沉香呋喃的骨架结构。(2)以苦皮藤素V和双呋喃二氢沉香呋喃为起始化合物,修饰合成一系列衍生物,其中一些化合物的杀虫活性高于天然产物苦皮藤素V。(3)作用机理研究结果表明:阻断昆虫神经-肌肉兴奋性接点电位的传导及对钙通道的抑制可能是麻醉成分苦皮藤素IV的主要作用机理;而和昆虫中肠肠细胞的特异性受体结合,从而改变细胞膜的结构,破坏细胞膜的正常功能可能是毒杀成分苦皮藤素V的主要作用机理。(4)研制出0.2%苦皮藤素乳油、0.15%苦皮藤素微乳剂及0.15%苦皮藤素微粉剂,其中0.2%苦皮藤素乳油于2001年投入批量生产,取得明显的经济效益和环境生态效益。

Advances in research of insecticidal plant Celastrus

Natural products with insecticidal activities could be a valuable resource for the discovery of new insecticides.The Chinese bittersweet,Celastrus angulatus,is a traditional insecticidal plant which is widely distributed over the Yellow River and Yangze River basins in China.Since 1985,we have studied on the bioactive compounds in the plant.By the activity-guided fractionation,51 compounds have been isolated from the extract of the root bark and leaves.All the compounds belong to sesquiterpene ployol esters and pyridine alkaloids with the β-dihydroagarofuran skeleton.A series of new dihydroagarofuran analogues were synthesized using difurano-β-dihydroagarofuran and celangulin V as the starting materials,some of these derivates had higher insecticidal activity than celangulin V.The results of primary toxicology research indicated that the main action mechanism of the narcotic active component celangulin IV might be to block the conduction of insect neuromuscular excitatory junction potentials and inhibit the Ca2+ channel of the insects,and that the main action mechanism of the insecticidal component celangulin V might be to bind with the receptor in the midgut of the insect,change the structure of the cell membrane,and disturb the normal function of the membrane.Three formulations(0.2% celangulin emulsifiable concentrate,0.15% celangulin microemulsion and 0.15% celangulin micropowder)were conferred patent right,and 0.2% celangulin EC has been produced commercially.