昆明山海棠的杀虫活性及有效成分

【目的】从天然产物尤其是植物中寻找杀虫活性物质是杀虫剂创制的重要途径。【方法】采用生物活性追踪、分离等方法，研究了昆明山海棠Tripterygium hypoglaucum (Levl.) Hutch对6种鳞翅目昆虫的杀虫活性及有效成分。【结果】昆明山海棠根皮石油醚提取物、甲醇提取物和乙酸乙酯提取物对粘虫3龄幼虫均具有拒食活性，24 h的拒食毒力AFC₅₀值分别为1 165.7 μg/mL、104.3 μg/mL和 47.3 μg/mL。昆明山海棠根皮甲醇提取物对粘虫4龄幼虫具有触杀活性，其LD₅₀值为100.4 μg/头。从昆明山海棠根皮甲醇提取物中分离出雷公藤春碱、雷公藤吉碱、雷公藤定碱和雷公藤榕碱 4个杀虫活性化合物，雷公藤春碱和雷公藤吉碱对粘虫具有胃毒麻醉活性，对粘虫3龄幼虫8 h的麻醉中量（ND₅₀）分别是18.1 μg/头和7.4 μg/头。雷公藤定碱和雷公藤榕碱对粘虫具有触杀麻醉活性，对粘虫4龄幼虫24 h的ND₅₀分别是0.33 μg/头和0.06 μg/头；对3龄小地老虎具有胃毒麻醉活性，24 h的麻醉中量ND₅₀分别是5.62 μg/头和1.24 μg/头。【结论】昆明山海棠对所测试的6种鳞翅目昆虫均有一定的杀虫活性，其主要杀虫活性成分为雷公藤春碱、雷公藤吉碱、雷公藤定碱和雷公藤榕碱4个化合物。

Insecticidal activities and active ingredients of Tripterygium hypoglaucum (Levl.) Hutch

【Aim】 Isolating insecticidal activities compounds is an important method to discover new pesticides. 【Methods】 Insecticidal activities and active ingredients of Tripterygium hypoglaucum against six lepidopteran insects were studied with bioassay-guided fractionation methods. 【Results】 The results showed the petroleum extract, methanol extract and acetic ether extract of the root of T. hypoglaucum had antifeedant activity against the 3th instar larvae of Mythimna separate Walker, with the AFC₅₀  value 1 165.7 μg/mL, 104.3 μg/mL and 47.3 μg/mL 24 h after treatment, respectively. The methanol extract of the root bark had contact toxicity to the 4th instar larvae of M. separatar, with the LD₅₀ values 100.4μg/larva 24 h after treatment. Four sesquiterpenes pyridine alkaloids, i.e., wilfortrine, wilforgine, wilfordine and wilforine, were isolated from the methanol extract of the root bark of T. hypoglaucum by bioassay-guided fractionation. The bioassay results showed that wilfortrine and wilforgine had stomach toxicity with the ND₅₀ value 18.1 μg/larva and 7.4 μg/larva,  respectively against M. separata; wilfordine and wilforine had topical toxicity with the ND₅₀ value 0.33 μg/larva and 0.06 μg/larva, respectively against M. separata and stomach toxicity with the ND₅₀ value 5.62 μg/larva and 1.24 μg/larva,  respectively against Agrotis ypsilon. 【Conclusions】 T. hypoglaucum exhibited insecticidal activity of some degree against the all six lepidopteran insects tested, and the main active ingredients were wilfortrine, wilforgine, wilfordine and wilforine.