Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China.
Toxins (Basel). 2023 Jan 24;15(2):105. doi: 10.3390/toxins15020105.
The red imported fire ant () is a worldwide invasive and dangerous insect that is controlled mainly by chemical insecticides. Plant-derived insecticidal compounds are generally better than synthetic insecticides for environmental compatibility and the biosafety of non-targets. The toxicity of the ethanol extract of roots against was evaluated under laboratory conditions. The ethanol extract showed toxicity against minor and medium workers of with 7-day LC values of 1426.25 and 2292.60 mg/L, respectively. By bioactivity-directed chromatographic separations using the minor worker as the test insect, two active compounds, matrine and sophocarpine, were isolated from the total alkaloids; their chemical structure was identified by C NMR data. Matrine showed toxicities against minor and medium workers with 7-day LC values of 46.77 and 71.49 mg/L, respectively, and for sophocarpine, 50.08 and 85.87 mg/L, respectively. The two compounds could substantially reduce the foraging response, food consumption, and aggregation of workers at a sublethal concentration of 15 mg/L. The present research suggests that roots have potential as a natural control agent for red imported fire ants.
红火蚁（）是一种具有全球入侵性和危险性的昆虫，主要通过化学杀虫剂进行控制。植物源杀虫化合物在环境相容性和非靶标生物的生物安全性方面通常优于合成杀虫剂。在实验室条件下，评估了苦参根的乙醇提取物对红火蚁的毒性。该乙醇提取物对小型和中型工蚁均具有毒性，其 7 天 LC 值分别为 1426.25 和 2292.60 mg/L。通过以小型工蚁为测试昆虫的生物活性导向色谱分离，从苦参总生物碱中分离出两种活性化合物：苦参碱和槐果碱；通过 C NMR 数据确定了它们的化学结构。苦参碱对小型和中型工蚁的毒性分别为 7 天 LC 值为 46.77 和 71.49 mg/L，槐果碱分别为 50.08 和 85.87 mg/L。这两种化合物在亚致死浓度 15 mg/L 时，可显著降低红火蚁工蚁的觅食反应、食物消耗和聚集。本研究表明，苦参根具有作为红火蚁天然控制剂的潜力。
