CuCl_2沉淀法去除草药提取液中鞣质的研究

Tannide Removal from Extracts of Medicinal Herbs by CuCl_2 Precipitation Method

提出了一种中药提取液去除鞣质的新方法--CuCl2沉淀法.利用鞣质分子中多个酚羟基作为配位体与Cu2+发生配合反应生成沉淀的特性,在保证药物有效成分不被破坏的同时,对茶果冬青、五味子、红景天、红景天复方、仙鹤草、山豆根、杜仲、枳实、防己、荷叶、紫苏等多种中药除鞣效率均可超过95%,药物的有效成分损失小,杂质离子的残留量低.试验考察了CuCl2加入量,pH值对鞣质去除率及药物有效成分损失率的影响.结果表明,随着CuCl2用量的增加溶液中鞣质的残留量也将达到一极限值,适宜的pH值为6.5～7.5.CuCl2沉淀法是一种新型、理想、高效的除鞣方法,适用于工业化生产.

A new method for tannide removal from extracts of medicinal herbs, i.e. CuCl2 precipitation method, was introduced. With the help of hydroxyl groups-in tannide molecules, tannide molecules could complex with Cu^2＋ to produce sediments. In the present processes, over 90% of removal efficiency of tannide, with only a small amount of components lost, and low residuals of impurities could be obtained for Dongqing, Wuwenzi, Hongjingtian, Compounds of Hongjingtian, Xianhe herbs, Shandougen, Duzhong, Zhishi, Fangji, Heye, Zisu etc.. Moreover, the effect of adding CuCI2 and pH on removal efficiency of tannide and the losing efficiency of virtual components were investigated, the results showed thal adding more CuCl2, the residuals of tannide would reach a limited value, and the proper pH was 6.5～7.5. This new method is ideal and efficient for tannide removal and is suitable for commercialized production.