苦丁茶中熊果酸的分离纯化研究

 目的研究苦丁茶(Ilex kudingcha C.J.Tseng)中熊果酸的分离纯化,建立分离纯化工艺条件,以利于苦丁茶资源的开发利用。方法以熊果酸浸出率为考核指标,采用正交实验法考察诸因素对浸出率的影响。乙醇提取液经沉淀富集和大孔树脂柱色谱纯化得到熊果酸,采用HPLC分析检测。结果优化的提取条件为:在85℃水浴中,以体积分数90％乙醇水溶液为提取溶剂。固液比为1:14,提取2次,每次提取2.5h,熊果酸的浸出率可达到1.44％。D₈树脂分离富集的最优条件:样品溶液熊果酸浓度1～2 mg·mL^-1,样品溶液pH=6.0～7.0,吸附1h,洗脱剂pH=11.0,依次用水、4倍体积30％乙醇、4倍体积90％乙醇以2～3mL·min^-1的流速洗脱,收集90％乙醇洗脱液,熊果酸回收率为97.82％,纯度为95.0％。结论 该工艺产品纯度高,收率高,可实现工业化。

Study on the separation and purification of ursolic acid from Ilex kudingcha

OBJECTIVE The separation and purification of ursolic acid from Ilex kudingcha C.J.Tseng was studied in order to exploit its resource.METHODS The effect of different factors on leaching rate was studied by orthogonal experiment and variance analysis. Ursolic acid was obtained by extraction, precipitation and macro-porous resin adsorption. The samples were analyzed by HPLC. The mobile phase consisted of alcohol and water, and the eluate was collected, in which, ursolic acid was detected at 220 nm. RESULTS The optimal conditions were obtained.The leaching rate of ursolic acid was up to 1.44% by reflux extraction using 90% alcohol for 2.5 h twice at 1:14 of Ilex kudingcha C. J. Tseng mass to solvent volume. The optimal conditions of separation and purification of D₈ resin included: the ursolic acid concentration was 1～2 mg·mL^-1 and the solution was pH 6.0～7.0, eluate was pH 11.0. After adsorpted for an hour, resin was eluted successively with water, four times volume 30% alcohol,four times volume 90% alcohol in the flow rate of 2～3 mL·min^-1. Ursolic acid product was acquired from 90% alcohol eluate.The purity of product was over 95% and the recovery was up to 97.82% . CONCLUSION The product was obtained with high purity and high recovery. It can be utilized in industrial production.