枸杞酸提取纯化工艺的研究

Study on Extraction and Purification Process of 2-O-(β-D-Glucopyranosyl) Ascorbic Acid

枸杞酸(AA2βG)是枸杞中特有的天然成分。试验旨在不破坏AA2βG结构的前提下,利用枸杞酸的物理及化学性质,筛选从枸杞中有效地提取、除杂及纯化枸杞酸的方法。试验摸索了不同沉淀剂、不同吸附填料和不同型号的阴离子树脂对枸杞酸的纯化效果。试验结果表明通过木质纤维柱的样品中枸杞酸含量大大提高,可达到15.68%。阴离子树脂筛选试验表明枸杞酸可以吸附在强碱阴离子树脂上,而无法吸附于弱阴离子树脂D315上。D201(HCO3-型)的树脂可以吸附AA2βG。0.5 mol/L NaHCO_3的洗脱液可以洗脱AA2βG,洗脱液过732树脂后不仅可以除去大量的Na+,将AA2βG-Na盐形式重新转化为有机酸形式,且置换形成的碳酸不稳定会大量分解为CO_2和H_2O,重新引入的杂质少,最终AA2βG的含量可达14.07%。试验为从枸杞中纯化AA2βG提供了基础。

2-O-（β-D-glucopyranosyl） ascorbic acid（AA2βG） is a natural ingredient in Chinese wolfberries. Under the premise of maintaining the structure of AA2βG, the aim of the report is to find out the most effective way to extract and purify AA2βG from Chinese wolfberries on the basis of the physical and chemical properties of AA2βG. The report studied the purifing effect of AA2βG by different kinds of precipitant, adsorbing filler and anion-resin columns as well as different anion resin groups and eluent. The result showed that the content of the sample which had passed through the wood fibre column could reach up to 15.68%. The study also showed that AA2βG could be absorbed in strong anion exchange resins just like D201（HCO3-）, yet it couldn＇t be absorbed in D315 weak anion exchange resin. 0.5 mol/L NaHCO_3 could elute AA2βG. After the elution solution passing through 732 column, large amount of Na＋ could be removed from the solution, the salt type of AA2βG could be transformed into organic acid type of AA2βG, and the formed instable carbonic acid could be decomposed into a large number of CO_2 and H_2O with little reintroduced impurities. Eventually, the content of AA2βG could reach up to 14.07%. The method could provide the scientific basis for the purifying process of AA2βG.