2019 Volume 25 Issue 2 Pages 187-195
A novel method was developed to separate the tea polyphenols epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) by two-step chromatography. In the first-step, four different macroporous absorption resins were compared by dynamic desorption, of which only AB-8 resin resulted in enriched fractions for EGCG and ECG. Their purity was 53.69%, and 65.77%, with recovery rates of 88.05%, and 83.46%, respectively. For the second-step, The recovery rates of 85.36% and 86.09% for EGCG and ECG were obtained respectively by a novel stationary phase of β-CD bonded agar gel. The overall recovery efficiency of the complete procedure was 75.16% for EGCG and 71.85% for ECG, respectively, and the purity of the obtained preparations reached 97.63% for EGCG and 98.09% for ECG. The chromatographic behavior of β-cyclodextrin bonded agar gel was studied with elution by acetonitrile, which indicated that both hydrophilic and hydrophobic interactions between the polyphenols and the solid phase occurred.
