Chemical Properties
Brown-yellow powder, soluble in organic solvents such as methanol, ethanol, and DMSO, derived from black tea.
Synthesis
A method for the preparation of theaflavin-3-gallate, using fresh lychee peel as a source of active polyphenol oxidase, and epigallocatechin gallate (EGCG) and epicatechin (EC) as raw materials for the preparation of theaflavin-3-gallate, which was then purified and separated by large-pore adsorbent resin column chromatography technique to prepare high-purity theaflavin-3-gallate; the method for the first time used the PPO in lychee peel as a catalyst to catalyze the synthesis of theaflavin-3-gallate, and separation and purification to obtain the high purity theaflavin-3-gallate, which solves the catalytic application of PPO in lychee peel in the synthesis of theaflavin-3-gallate, and the method is highly efficient, reproducible and stable. Specifically, it includes the following steps: S1) extraction of lychee polyphenol oxidase: weighing fresh lychee peels, adding buffer, mashing and filtering, retaining the filtrate; adding buffer to the filtrate residue, stirring, filtering, retaining the filtrate; combining the two filtrates, then centrifuging, and taking the supernatant that is the lychee polyphenol oxidase solution; S2) preparation of the crude solution of theaflavin-3-gallate: weighing epigallocatechin gallate (EGCG) and epigallocatechin (EC), add buffer to dissolve fully, then add the lychee polyphenol oxidase solution described in step S1) and hydrogen peroxide solution, stirring reaction, filtration, retention of filtrate, that is, the theaflavin-3-gallate crude solution; S3) theaflavin-3-gallate crude purification: the theaflavin-3-gallate crude solution obtained in step 2) was used as a column chromatograph, and then as a column chromatograph, and then as a column chromatograph. S3) purification of crude theaflavin-3-gallate: the crude solution of the theaflavin-3-gallate obtained in step 2) is gradually added to a column chromatography column equipped with a macroporous adsorbent resin as a column chromatography sampling solution, eluted first with an aqueous solution at the end of the sampling, and then with an alcoholic solution, and the alcoholic eluate is collected, and the alcoholic eluate collected is concentrated under reduced pressure to be free of alcoholic flavor, and freeze-dried, i.e., the theaflavin-3-gallate is obtained.
