超临界CO_2萃取杜仲叶黄酮类化合物工艺优化

Optimization of supercritical CO_2 extraction processing of flavonoids in Eucommia ulmoides leaves

以杜仲叶为原料,采用超临界CO_2萃取法,对其黄酮类化合物的提取工艺进行优化。首先采用单因素实验分别探讨了杜仲叶采摘期、夹带剂(乙醇)的浓度、萃取温度、萃取压力、萃取时间和CO_2流速对黄酮类化合物得率的影响,并通过正交实验对杜仲叶黄酮类化合物的最佳萃取工艺条件进行优化,然后再对萃取物分离纯化溶剂的种类及用量进行探讨。研究结果表明,提取黄酮类化合物较为适宜的杜仲叶采摘期为6月份,添加浓度为80%(v/v)的乙醇3.5mL/g作夹带剂时最佳萃取条件为:萃取温度40℃、萃取压力25MPa、萃取时间2.5h、CO_2流速200kg/h,然后将萃取物加1:3(v:v)的乙醚分离出黄酮类化合物,得率可达2.032%(w/w)。

The supercritical CO2 extraction processing of flavonoids was optimized with Eucommia ulmoides leaves as raw material. Firstly, the effect of the Eucommia ulmoides leaves picking period, entrainer （ethanol） concentration, extraction temperature, extraction pressure, extraction time and the flow velocity of CO2 on fiavonoids extraction rate were discussed respectively by the single factor experiments, and the optimum conditions were optimized by the orthogonal experiment. Then, the types and amounts of separation and purification solvents of extracts were investigated.The results showed that,the suitable picking period of Eucommia ulmoides leaves was June for extraction flavonoids, and the best extraction conditions by adding 80% （v/v） ethanol 3.5mL/g as the entrainer were as follows： extraction temperature 40℃, extraction pressure 25MPa, extraction time 2.5h,the flow velocity of CO2200kg/h,and then the flavonoids could be separated from extracts by adding 1：3（v/ v） ether.Under these conditions,the extraction rate of flavonoids could reach 2.032% （w/w）.