ABSTRACT
<p><b>OBJECTIVE</b>To purify caffeic acid tetramer (CAT) with macroporous resin on the basis of its fundamental physicochemical stability research.</p><p><b>METHOD</b>The changes of CAT content were compared by HPLC method before and after the purification process, or while other conditions were altered.</p><p><b>RESULT</b>LK001 was the best one among 7 kinds of macroporous resin in regard of purifying ability. The optimum absorbing technology was the solution concentration at 10 g x L(-1), pH at 4.5, and the flow rate at 3 BV x h(-1). The best eluting technology was 45% ethanol as eluting agent, pH at 5.0, eluting volume at 50 mL after applying super-purified water and 20% ethanol. The yield of product was 3. 6 percent, and the active compound CAT was 58 percent in the product.</p><p><b>CONCLUSION</b>Macroporous resin LK001 is effective in enriching CAT from the crude extracts, thus this method of purification is advisable.</p>