METHODS OF SEPARATING CATECHINS FROM GREEN TEA LEAVES

摘要

There have been a number of reports on the isolation of (-)-EGCG from green tea. However, the presence of many components with their similar water solubility and the structural similarities of the catechins make the isolation of pure (-)-EGCG difficult. The absence of a simple, efficient and inexpensive method of obtaining pure (-)-EGCG has hampered the evaluations of (-)-EGCG in animal and human clinical studies. This invention provides a method of isolating catechins, including (-)-EGCG, by first converting the catechins to their respective ester forms. The esterified catechins are then separated by chromatography, and converted back to catechins. The method of this invention is relatively simple, and a substantial amount of catechins may be obtained.