枇杷叶中五环三萜酸类有效成分的提取研究

目的：进行枇杷叶中五环三萜酸类有效成分的提取方法研究。方法：称取干燥粉碎的枇杷叶5g，以乙醇为溶剂，水浴中回流、过滤，滤液用旋转蒸发仪浓缩得到浸膏，浸膏用乙醇溶解、稀释，经香草醛显色后，在548nm处测定紫外吸收。单因素实验考察了不同水浴温度（60℃、70℃、80℃、90℃）、提取时间（2h、3h、4h、5h）、料液比（1∶10、1∶15、1∶20、1∶25、1∶30）、乙醇浓度（60%、70%、80%、90％）的影响，并进行了L16（44）的正交实验。结果：以乌索酸为对照建立标准曲线，曲线方程为A=0.021C＋0.0249，相关系数r2=0.9995，线性范围为10～50μg/mL，线性关系良好。正交实验结果表明，乙醇体积为90%，提取温度为80℃，提取时间为5h，料液比为1∶20为最佳提取条件。在该条件下进行提取实验验证，结果表明枇杷叶中总五环三萜类成分的含量约为1.32%。结论：该方法简便易行，可用于枇杷叶中五环三萜酸类有效成分的提取。

Extraction of Pentacyclic Triterpenoid Acids from Loquat as the Active Ingredients

Aim:To study the extraction methods of pentacyclic triterpenoid acids from loquat as the active ingredients of loquat. Methods:Weigh dry pulverized loquat 5g, add ethanol as the extraction solvent, reflux in the hot water bath, then filter it and the filtrate is concentrated on a rotary evaporator to give the extract, then the extract is dissolved with ethanol, diluted by vanillin color, measure the absorption at the UV wavelegth of 548nm. Single factor experiments with different temperatures of the water bath(60℃, 70℃, 80℃, and 90℃), different extraction time (2h, 3h, 4h, and 5h), different solid-liquid ratios (1∶10,1∶15,1∶20,1∶25,1∶30), and different ethanol concentrations(60%, 70%, 80%, 90%)were conducted respectively. An orthogonal experiment(L16(44)) was also investigated. Results:Ursolic acid was used as a standard to establish the standard curve with the equation of A=0.021C+0.0249, the correlation coefficient of r2=0.9995, and the linear range of 10~50μg/mL. The results showed that there was a good linear relationship between the UV absorption and the concentration of the solution. The orthogonal experiment results showed that the best result can been get with the extraction conditions of 90% ethanol, extraction temperature of 80℃, extraction time of 5h, and solid-liquid ratio of 1∶20. The results under this optimum extraction condition showed that the total content of pentacyclic triterpenoids in loquat was about 1.32%. Conclution: The method is simple and easy to perform, and can be used to extract pentacyclic triterpenoid acids as the active ingredients from loquat.