灰毛豆种子中化学成分的鉴定及其对黑翅土白蚁的杀虫活性

摘要

In order to determine insecticidal compounds from the methanol extracts of Tephrosia purpurea seeds and their insecticidal activities against the adult of Odontotermes formosanus, active compounds were isolated with column chromatography and their structures were established by NMR spectroscopy, as well as by HR-MS analysis. Contact, repellent and transmission toxicities of each compound were determined against the adult of O. formosanus. Ten known compounds were isolated and identified (Obovatachalcone, Obovatin, Isolonchocarpin, Rotenone, Pongachin, 12α-hydroxyrotenone, 6α, 12α-dehydrodeguelin, Tephrosin, Penduletin, Raffinose). Five of the ten compounds showed insecticidal activity against the adult of O. formosanus. Five compounds (Isolonchocarpin, Tephrosin, Obovatin, 12α-hydroxyrotenone and Rotenone) exhibited contact toxicity, with LD50 of 93.9, 123.5, 209.1, 259.4 and 370.8 µg per insect at 24 hours after treatment, respectively; and three compounds (Obovatin, Rotenone and 12α-hydroxyrotenone) exhibited transmission toxicity, with cumulative poisoning rate of 24.3,38.7 and 100% at 56 hours after treatment, respectively. At the dosage of 500 mg·L−1, two compounds (Isolonchocarpin and Tephrosin) exhibited weak repellent toxicity. The results suggested that 12α-hydroxyrotenone was the most potential active compound against O. formosanus.%　　为探明灰毛豆 Tephrosia purpurea 种子中的杀虫成分及其对黑翅土白蚁 Odontotermes formosanus 工蚁成虫的杀虫活性，对其甲醇提取物采用多种色谱技术分离纯化，结合核磁共振图谱和质谱方法鉴定化合物的结构，并测定了各化合物对黑翅土白蚁工蚁成虫的触杀、忌避和传毒活性。从灰毛豆种子甲醇提取物中分离鉴定了10个化合物，即 Obovatachalcone，Obovatin，异合生果素，鱼藤酮，Pongachin，12α-羟基鱼藤酮，6a,12a-脱氢灰叶酚，灰叶素，Penduletin 和棉子糖。5个化合物（异合生果素，灰叶素， Obovatin，12α-羟基鱼藤酮和鱼藤酮）表现出触杀活性，处理后24 h 的 LD50值分别为每虫93.9，123.5，209.1，259.4和370.8µg；3个化合物（Obovatin，鱼藤酮和12α-羟基鱼藤酮）表现出传毒活性，处理后56 h 累积中毒率达24.3，38.7和100%；2个化合物（异合生果素和灰叶素）在处理浓度为300 mg·L−1时表现出较弱的忌避活性。结果表明，化合物12α-羟基鱼藤酮对黑翅土白蚁工蚁成虫无忌避性，有一定的触杀活性，在群体中的毒性传播能力强，可进一步研究用于白蚁防治。