Preparative Separation of EGCG from Korean Green Tea by Reversed-Phase High-Performance Liquid Chromatography

초록

Among catechin compounds abundant mainly in green tea, EGCG, (-)epigallocatechin gallate, has anti-oxidative and anticarcinogenic properties. Korean green tea cultivated at Bosung (Chonnam) was used as feed sample. The purpose of this work is to develop the pretreatment steps and to find the mobile phase composition of RP–HPLC at isocratic mode in order to separate preparatively EGCG from Korean green tea. The separation was done by a C18 preparative column (22´250 mm, 40-63㎛) with the mobile phases of 0.1% acetic acid in water, acetonitrile, methanol, and ethyl acetate considered. The flow rate of mobile phase was fixed at 25ml/min. Initially, catechin compounds from green tea were extracted by distilled water at 50oC. The extract was partitioned with an equal volume of chloroform to eliminate impurities. Catechin compounds were extracted from the water layer with an equal volume of ethyl acetate. From the experimental results, the optimum mobile phase condition for separating EGCG from Korean green tea was 0.1% acetic acid in water/acetonitrile/methanol/ethyl acetate (84/12/1/3 vol.%) in isocratic mode with the retention time of EGCG, 8.4 min. With the experimental condition, the maximum amount of EGCG completely separated was 0.6mg in a single run.