Extraction And Purification Of EGCG And Theaflavins In Tea

Epigallocatechin gallate(EGCG) and theaflavins are natural products in tea, they all have effects like anti-oxidation, preventing cardiovascular disease, reducing blood fat, anti-cancer and pharmacological functions. Products of high purity have huge economic value and they are widely used in many fields. It’s significant to find methods of separating and purifying EGCG and theaflavin of high purity.The essay discussed the mobile phase for safety and determined the proportion of ethanol and water based on the HPLC method using PS-DVB as the padding packed in chromatographic column(4.6x250nm).Then PS-DVB was put into Flash chromatographic column(36.6x207nm), in preparation of medium pressure liquid chromatography, the product purity, yield and recovery rate was taken as the main index to optimize the proportion and flow rate of mobile phase as well as loading quantity of samples. Finally the best conditions were achieved:flow rate:lOmL/min, mobile phase:ethanol/water=30/70(v/v),loading quantity:900mg. On this condition, the crude products were purified from 71.1% to 97.02% and the recovery rate was 75.81%.The process had large capacity and was safe, quick, convenient for production and provided effective technical support for EGCG production.HZ-816 resin was selected as the best resin to purify theaflavin by static adsorption, then penetration volume, elution type and concentration was discussed through dynamic elution experiment. The effect between loading flow rate, concentration, elution volume and the purification was also determined. At last the paper discussed the recovery and the stability of HZ-816.Finally automatic preparation chromatography under the best purification condition, the conditions were:40mg/mL crude products(3BV) were loaded at the speed of 2BV/h, the residual solution was washed with 1BV deionized water.2BV 30% ethanol aqueous solution was taken to remove impurities,4BV aqueous solution of 60% ethanol eluted theaflavins products with automatic collector to collect effluent, the resin was recovered with 5BV ethanol hydrochloric acid solution. Theaflavin powders were got through distillation, vacuum freeze drying. The purification and recovery rate by HPLC tested were 90.8% and 56%.The method was simple and could make continuous production come true, the process provided a new idea for mass production of theaflavins.