Separation purification method of catechin monomer

Abstract

The invention relates to a method for separating and purifying catechin monomers EGCG and ECG. Its characteristics are: Sephadex LH-20 is used as column filler, absolute ethanol is used as eluent; then Sephadex LH-20 column is used as eluent, and 40% ethanol aqueous solution is used as eluent. Column chromatography; that is, the non-gradient one-time separation of the chromatography column. Compared with the original method, the method of the invention greatly simplifies the separation and purification equipment of the catechin monomer, has the advantages of simple method, low cost, non-toxic solvent, short separation cycle, high monomer extraction rate and product purity.

Description

Technical field [0001] The invention relates to a method for separating and purifying two types of important catechin monomers, L-epigallocatechin gallate EGCG and L-epicatechin gallate ECG, in tea. Background technique [0002] Catechin is an important natural active substance in tea. It belongs to the flavanol compound. It was first extracted and isolated by the Japanese in 1929. It is composed of about eight kinds of monomers, namely D, L-catechin (D, LC), L-epicatechin (L-EC), L-epigallocatechin (L-EGC), D , L-gallocatechin (D, L-GC), L-epicatechin gallate (L-ECG), L-catechin acid ester (L-CG), L-epigallocatechin Gallic acid ester (L-EGCG), L-gallocatechin gallic acid ester (L-GCG). Since the esterification of catechins and gallic acid occurs in CG, ECG, GCG, and EGCG, they are called ester catechins; and C, EC, GC, and EGC that do not have esterification are called non-esterification. Ester-type catechins, the structure of each catechin is relatively similar, some are isomer...

AI Technical Summary

Problems solved by technology

For the isomer GCG with EGCG, the current report can only be separated by preparative HPLC

In addition, the eluent used in the dextran gel chromatography method also has the disadvantages of long elution time and easy oxidation of the product.

[0016] (2) High separation cost

Due to the high price of preparative HPLC chromatographic column, and it is easy to be polluted and blocked, the service life is short, the production cost is high, and the one-time sample volume is small (about 1 mL for each injection volume), and the purification cycle is long

[0018] (3) Toxic solvent residue

[0019] At present, the semi-preparative HPLC method widely used at home and abroad has relatively complicated purification solvents in the later stage. Most of them are ternary mixed solvents, and contain toxic solvents such as methanol and tetrahydrofuran, which are difficult to recover and eliminate, which restricts the application field of the product.

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