苦丁茶中绿原酸及其异构体的提取变化分析

以富含绿原酸类成分的苦丁茶(Ilex kaushue)为材料，使用溶剂甲醇、乙醇、丙酮和水，结合超声波提取、水浴提取、回流提取等方法对绿原酸及其异构体的提取效率及提取后各异构体的变化进行分析。应用超高效液相色谱法可使苦丁茶的6种绿原酸类成分及咖啡酸在6 min内实现分离。提取结果表明，丙酮作为提取溶剂，在采用超声波和水浴提取时能获得较高的提取效率，易获得较多总量的绿原酸类成分和高含量异绿原酸A。而最常用的溶剂乙醇并未达到理想的提取效果。在不同溶剂的回流提取中，虽然提取的绿原酸类成分总量接近，但异绿原酸A和异绿原酸C含量有较大差异。醇溶液特别是乙醇溶液的回流提取使异绿原酸C的量大幅增加，而相应的异绿原酸A的量大幅减少，表明在醇加热条件下，异绿原酸A转化为异绿原酸C，这为获得抗氧化性更强的异绿原酸C提供了新思路。

Variations of Chlorogenic Acid Isomers in the Solvent Extraction from Kudingcha (Ilex kaushue)

Kudingcha, which is rich in chlorogenic acid, was used as material, the extraction efficiency of chlorogenic acid isomers and changes of isomers after extraction were investigated by using methanol, ethanol, acetone and water, combined with the commonly used ultrasonic extraction, water bath extraction and reflux extraction. Six chlorogenic acid isomers and caffeic acid from Kudingcha could be separated within 6 minutes by ultra performance liquid chromatography (UPLC). The results showed that acetone used as extraction solvent could obtain higher extraction efficiency in ultrasonic and water bath, and it was easy to obtain more high content of total chlorogenic acids and isochlorogenic acid A. However, the most commonly used solvent ethanol could not perform the ideal extraction effect under the set conditions of ultrasonic wave and water bath extraction. In the reflux extraction of different solvents, although the total amount of chlorogenic acids extracted was similar, the contents of isochlorogenic acid A and isochlorogenic acid C showed great differences. The reflux extraction of alcohol solution, especially ethanol solution, greatly increased the amount of isochlorogenic acid C, and the corresponding amount of isochlorogenic acid A decreased significantly, which indicated that under the condition of alcohol heating, isochlorogenic acid A was converted into isochlorogenic acid C, which also provided a new and simple method for obtaining isochlorogenic acid C, the ingredient with stronger antioxidant capacity.