A simple preparative chromatographic separation of green tea catechins.

A simple separation method was developed for tea catechins by using Sephadex LH-20 column chromatography and preparative HPLC. A sample green tea solution was prepared with boiling water. From the sample solution, crude catechin A mixture and B mixture were efficiently separated by stepwies chromatography on Sephadex LH-20 with aqueous acetone. The A mixture contained free-type catechins [(-)-epicatechin (EC) and (-)-epigallocatechin (EGC)], and B mixture contained ester-type catechins [(-)-epicatechingal-late (ECg) and (-)-epigallocatechingallate (EGCg)]. ECg and EGCg of B mixture were separated simply on CAPCELL PAK C18 with 25% methanol (v/v) by preparative HPLC. The purity of ECg and EGCg powder finally obtained was about 95% and 92%, respectively.