杜仲叶和皮中杜仲胶提取的研究

Extraction of Gutta-Percha from the Bark and the Leaves of Eucommia (Eucommia ulmoides)

以石油醚为提取剂 ,杜仲叶和皮经过硫酸或氢氧化钠水溶液处理后 ,能提高杜仲胶的提取率。但硫酸浓度太高会导致杜仲胶降解 ,而用碱处理不会发生此现象。提取液经蒸馏适量回收溶剂后 ,再以乙醇为沉淀剂 ,丙酮为脱色剂制得白色富有弹性的杜仲精胶。

Gutta percha is extracted from leaves and bark of Eucommia in Soxhlet's extractor using petroleum ether (boiling range 60～90℃) as extraction agent.If leaves and bark of Eucommia have been cooked before,the extraction yield of gutta percha is greatly raised.After extraction solution is vapprized and concentrated to a certain extent,ethanol,as a precipitant,is added to it to help isolate gutta percha.Then acetone is used as a decolorant to make the raw gutta percha into pure rubber.Alcohol cannot solve gutta percha.However,it is very hard to recover the gutta percha when using chloroform as extraction agent.The cooked solutions and extraction solution can be used to recover natural medicines.