Separation of epigallocatechin gallate from Korean green tea by RP-HPLC

Catechin compounds, abundant mainly in green tea, have chemo-preventive effects against carcinogenesis. The green tea used in this experiment was cultivated at Bosung (Chonnam, Korea) and purchased from a domestic market. The extract at 50 degreesC water from the powder of Korean green tea was partitioned with chloroform and ethyl acetate. The resulting solution was further purified on a preparative column (4.6x250 mm, 15 mum). Finally separation was achieved on a mu -Bondapak C-18 (3.9x300 mm, 10 mum) column. The elution orders of the catechin compounds contained in the green tea were EGC, C, EC, EGCG, and ECG. Identification of EGCG was confirmed by the standard chemical. The content of EGCG was 121.3 mg/5 g of dry Korean green tea and the purity was higher than 98%. In preparative separation, the optimum mobile phase for isolating EGCG from the extract consisted of 0.1% acetic acid in water/ethyl acetate/acetonitrile, 87/1/12 vol.% with 1.0 mL/min of the mobile phase flow rate.