Preparative Purification of Epigallocatechin-3-gallate (EGCG) from Tea Polyphenols by Adsorption Column Chromatography.

In order to separate epigallocatechin-3-gallate (EGCG) from tea polyphenols, the adsorption ability of resins chosen toward catechins was investigated. According to static adsorption results of resins selected, polyamide displayed better selective adsorption ability between esterified and non-esterified catechins, and LSA-10 distinguished EGCG from ECG very well among esterified catechins. Therefore, columns packed with polyamide and resin LSA-10 were adopted in the first and second purification of EGCG, respectively. After the first-run purification, the product can be obtained with a 70.27 % EGCG purity and 80.21 % recovery. After the second-run separation, product contained an EGCG purity of 95.14 % and a total recovery of 76.78 % can be achieved. Moreover, a higher per volume adsorption material load amount 51.02 mg mL tea polyphenols and yield 24.11 mg mL EGCG were obtained in the study. Furthermore, only ethanol solution was used as elution reagent in the process. In the study, a method that is environmentally friendly, with lower cost and better repeatability has been developed. This result will be of help in development of tea resources and applications on a large scale. [ABSTRACT FROM AUTHOR]