胡芦巴超临界CO2萃取物的萃取条件优化及其对谷蠹的触杀活性

对胡芦巴Trigonella foenum-graecum L.中杀虫活性成分进行超临界CO₂萃取分离，并以主要储粮害虫谷蠹Rhyzopertha dominica Fabricius为对象，对其触杀活性进行研究。采用正交试验设计，以萃取液中活性成分的得率、毒力为考察指标，对杀虫活性成分的提取条件进行优化。结果表明：最佳萃取工艺为萃取压力25 MPa，萃取温度55℃，夹带剂为95%乙醇，固液比为200 g:30 mL。萃取压力和夹带剂体积对试验指标有非常显著的影响，萃取温度和夹带剂浓度的影响较小。优化后的萃取方案可达到5.96%的得率。萃取产物对谷蠹的触杀试验结果显示，优化后的超临界CO₂萃取工艺对胡芦巴中的杀虫物质具有良好的选择性，得到的萃取物对谷蠹处理10天后的致死中浓度为65.03 μg/cm²，触杀活性明显增加。

Extract from Trigonella foenum-graecum L.by the optimized SFE-CO2 extraction method and its contact toxicity to Rhyzopertha dominica Fabricius

Extraction of insecticide constituents from Trigonella foenum-graecum L. by supercritical fluid CO₂ extraction (SFE-CO₂) method was optimized and the contact toxicity of extracts to Rhyzopertha dominica Fabricius were assayed. The extraction method was optimized with orthogonal design experiments. Contact toxicity and efficiency of extraction were used as value standards. The results showed that the optimal extraction was achieved at 55℃ under 25 MPa of pressure,  the modifier was 95% alcohol,  and the rate between seeds powder and modifier was 200 g∶30 mL. Extraction pressure and modifier volume showed significant effect to extraction procedure, while extraction temperature and modifier concentration showed less effect. The extracts loaded on filter paper showed toxicity to adult R. dominica. An extraction rate of 5.96% was achieved at theoptimal condition,  and the toxicity was increased obviously with the LC₅₀ value of 65.03 μg/cm² for R. dominica treated on filter paper for 3 days and then cultured normally for one week. The results indicated that the extracts have high insecticide activity on R. dominica.