甘草提取物中甘草次酸的精制工艺研究

Extraction and Purification Techniques of Glycyrrhetinic Acid in Liquorice Extract

关键词:  甘草提取物  甘草次酸  精制  阴离子交换树脂

Key words:  liquorice extract  glycyrrhetinic acid  extraction  anion exchange resin

摘要:

目的 优选甘草提取物中甘草次酸的精制工艺。方法 以甘草次酸的转移率和含量为指标，单因素筛选甘草的粗提取工艺，进一步筛选和优化阴离子交换树脂对甘草次酸的纯化过程。结果 甘草的粗提取工艺为将甘草药材用20%乙醇回流提取3次，每次10倍药材体积，合并提取液浓缩至相对药材5倍体积，加入50%硫酸，使浓缩液中的硫酸浓度为5%，加热回流5 h，放冷，弃去酸液，水洗沉淀至中性，烘干，研细，得甘草次酸粗产品；精制工艺为将甘草次酸粗产品用适量水稀释，调节pH至11，过阴离子交换树脂柱，盐酸酸化，10倍量85%以上乙醇洗脱，减压回收乙醇，将析出的沉淀过滤，50℃以下干燥，得黄棕色粉末，甘草次酸含量为55.5%，转移率为53.3%。结论 制备得到的甘草次酸含量较高，采用阴离子交换树脂提取纯化甘草次酸的工艺可行。

Abstract:

OBJECTIVE To optimize the extraction and purification techniques of glycyrrhetinic acid(GA) in liquorice extract. METHODS With the transfer rate and content of GA as the index, the crude extraction process of Glycyrrhiza uralensis was screened by single factor. Then the purification process of GA by anion exchange resin was further screened by single factor. RESULTS The extraction process of GA was determined as follows:The liquorice was immersed with 20% ethanol for reflux extraction 3 times, 10 times volume of liquorice each time, the extract was concentrated to 5 times volume of liquorice. Added 50% sulfuric acid, made the concentrate containing 5% sulfuric acid, heatedreflux for 5 h, abandoned the acid, washed to neutral and dry, porphyrized and liquorice obtained the GA extract. And the process of purification of GA was added appropriate amount of water to the extract, adjust pH to 11, made through the anion exchange resin column, added hydrochloric acid for acidification, eluted with 10 times 85% ethanol or more, evaporated ethanol under reduced pressure, filtered the precipitate, dry the filtrate below 50℃, obtained brown powder. The content of glycyrrhetinic acid was 55.5%, transfer rate was 53.3%. CONCLUSION The high content of GA obtained by the preparation indicates that the extraction and purification of GA by anion exchange resin is feasible.