不同增溶剂对超临界CO_2提取虎杖中白藜芦醇和大黄素影响的研究

Extraction of Resveratrol and Emondin from Polygonum cuspidatum by Supercritical CO_2 with Different Solubilizers

目的考察不同增溶剂、提取压强、提取次数对采用超临界CO2(SC-CO2)提取虎杖中白藜芦醇和大黄素提取效果的影响,并与常用的回流提取法进行比较。方法选用丁二酸二异辛酯磺酸钠(AOT)、聚维酮(PVP k-90)、泊洛沙姆(Poloxamer 188)、聚山梨酯-80、乙醇作为增溶剂,采用SC-CO2提取虎杖中的白藜芦醇和大黄素,结合单因素优选最佳提取条件,并与回流提取法进行比较。结果使用AOT作增溶剂时白藜芦醇提取率最高,为0.304 mg/g;而使用乙醇作为增溶剂时提取率最低,仅为0.015 mg/g。大黄素的提取率受增溶剂的影响相对较小,使用PVP时提取率最高,为1.008 mg/g,而使用聚山梨酯-80提取率最低,为0.679 mg/g,但与使用乙醇的提取率(0.745 mg/g)不存在显著差异(P>0.05)。通过单因素获得最佳提取工艺:P=25 MPa、T=50℃、AOT浓度为0.05 mol/L、提取次数为3次,在此条件下白藜芦醇的提取率为0.31 mg/g、大黄素提取率为0.97 mg/g;与回流提取法相比,大黄素的提取率增加了86.5%,而白藜芦醇的提取率降低了81.5%。结论 AOT、PVP K-90、Poloxamer 188能够提高SC-CO2提取白藜芦醇和大黄素的提取率,SC-CO2作为一种新兴中药提取技术,具有提取效果好、低温提取、流程简单、绿色环保等特点,该法可用于虎杖中白藜芦醇和大黄素的提取,但更适合大黄素的提取。

Objective To explore the effect of different solubilizers, pressure and extract time in the extraction of resveratrol and emondin by supercritical CO2 （SCE）. Methods Resveratrol and emondin were extracted from Polygonum cuspidatum by SCE with different solubilizers, including AOT, PVP k-90, Poloxamer 188, and Tween 80. The parameters of SCE such as concentration of solubilizer, pressure, and extraction times were optimized. The extraction results were compared with heat reflux extraction. Results： The results show that resveratrol was hardly extracted by SCE with ethanol as modifier （ the yield was 0.015 mg/g） , but AOT could enhance the extraction yield of resveratrol significantly （the yield was O. 304 rag/g）, while the yield of emodin was influenced gently by using these solubilizers. The yield of emodin was highest （1. 008 mg/g） when PVP was used as modifier, but when the Tween 80 was used the yield was the lowest （0. 679 mg/g）. The optimal process was as follow： pressure at 25 MPa, temperature at 50℃, the concentration of AOT was 0.05 mol/L and extracted for 3 times. Under this condition the yield of resveratrol was 0.31 mg/g which was dropped by 81.5% than extracted by heat reflux extraction. The yield of emondin was 0. 97 mg/g which was increased by 86.5% than extracted by heat reflux extraction. Conclusion： The yields of resveratrol and emondin extraction from Polygonum cuspidatum by SCE can be improved by introducing AOT, PVP k-90 and Poloxamer 188 into supercritical COz. Based on the comparison of SCE and heat reflux extraction, the advantage of SCE is less extraction time at lower operating temperature without using large amount of organic solvent.