Studies On Sevsralinsecticidal Alkaloids Isolated From Tripterygium Wilfordii Hook

Botanical pesticides with low toxicity, low-residue, safe to the environment, harmless tohumans and animals, pests difficult to generate resistance, is one of the main developmentdirection of new pesticides. Tripterygium wilfordii Hook is an important traditional Chinesemedicine, and also a traditional botanical insecticides. A series of studies on Tripterygiumwilfordii Hook had proved that alkaloids from the root bark of Tripterygium wilfordii Hookare the main insecticidal compositions by Research&Development Center of BiorationalPesticide, Northwest A&F University. In this study, the insecticidal activities of severalalkaloids isolated from Tripterygium wilfordii Hook had been studied in order to verify themain insecticidal alkaloid which are the high-performance components. The main results weregiven as follows:1. The chemical constituents of total alkaloid from the root bark of Tripterygium wilfordiiHook had been studied by means of modern separation and purification ways(¹H-NMR,¹³C-NMR,IR,ESI-MS).7compounds were isolated from the total alkaloid and thestructures of7compounds were elucidated as Wilforjine (K0),1-Desacetylwilforgine(K1),Wilforgine(K2),1-Desacetylwilforine(K3), Wilforine(K4), Wilfotrine (K5) and PeritassinesA (K6)；2. The insecticidal activities of7compounds were tested by leaf disk method, topicalapplication and the leaf sandwich method. The result showed that all tested compounds haveno contact toxicity against Plutella xylostella (L.),Mythimna separatea (Walker),Pieris rapaeL.,Myzus persicae(Sulzer) and Sitophilus zeamais Motschulsky;1-Desacetylwilforgine(K1),Wilforgine(K2),1-Desacetylwilforine(K3) and Wilforine(K4) have antifeedant andnarcotization activity against Mythimna separatea (Walker),Pieris rapae L and Plutellaxylostella (L.); Wilforgine,1-Desacetylwilforine and Wilforine have antifeedant andarcotization activity against Plutella xylostella (L.) and Mythimna separatea (Walker). The24h post treatment AFC50of Wilforgine,1-Desacetylwilforine and Wilforine against3rd instarlarvae of Mythimna separatea (Walker) are17.24,33.52and4.10g/mL;48h post treatmentKD50are630,212.17and100.89g/mL respectively. The24h AFC50of Wilforgine,1-Desacetylwilforine and Wilforine against Plutella xylostella (L.) are54.62,55.19and36.65g/mL;48h post treatment KD50are164.43,337.66and96.42g/mL.1-Desacetylwilforgine, Wilforgine,1-Desacetylwilforine and Wilforine also have poisonousactivity against4th instar larvae of Culex pipiens pallenss Coquillett and know-down andpoisonous activity against Musca domestica Linnaeus. This is the first report on insecticidalactivity of Wilforjine,1-Desacetylwilforgine,1-Desacetylwilforine and Peritassines A; 3. Wilforgine and Wilforine are the the main insecticidal active ingredients of the7alkaloidsfrom Tripterygium wilfordii Hook.