A RAPID CHROMATOGRAPHIC METHOD FOR SEPARATION OF INDIVIDUAL CATECHINSFROM GREEN TEA

Catechins from Chinese green tea were extracted into hot water and wer e partially purified using a counter-current chromatographic procedure . Solvent systems employed were water/chloroform (1:1, v/v) and water/ ethyl acetate (1:1, v/v). Crude catechins so obtained were subjected t o Sephadex LH-20 column chromatography using ethanol as the solvent. E luate fractions, as such, were analyzed by measuring their absorbances at 280 nm, and at 500 nm after colour development reactions for catec hins. Separated fractions by column chromatography were also monitored using silica gel thin layer chromatographic plates. Sephadex LH-20 pr ovided a rapid method for separation of (-)epicatechin, (-)epigallocat echin, (-)epicatechin-3-gallate and (-)epigallocatechin-3-gallate. Sem i-preparative high performance liquid chromatography on RP-18 column w ith a water/acetonitrile/methanol/acetic acid (79.5:18:2:0.5, v/v/v/v) mobile phase successfully separated individual catechins from other p henolics. Chemical structures of purified catechins were further confi rmed by H-1-NMR spectroscopy. Copyright (C) 1996 Canadian Institute of Food Science and Technology