Separation purification method of catechin monomer

Abstract

This invention relates to separation and purification method of catechin monomer EGCG and ECG. The features are that dextrane gel Sephadex LH-20 is column filling and eluant is absolute ethyl alcohol. Then column chromatography is made by dextrane gel Sephadex LH-20 and 40% ethanol aqueous solution be eluant, that is chromatography column non- gradient expendable separation is adopted. Comparing to original method, equipments are facilitated greatly and the method is simple, cost is low. The solvent is nontoxic and separation period is short, and monomer extraction rate and product purity are both high.

Description

technical field [0001] The invention relates to a separation and purification method of two important catechin monomers L-epicatechin gallate EGCG and L-epicatechin gallate ECG in tea leaves. Background technique [0002] Catechin is an important class of natural active substances in tea, which belongs to flavanol compounds. It was first extracted and isolated by the Japanese in 1929. It consists of about eight monomers, namely D, L-catechin (D, L-C), L-epicatechin (L-EC), L-epigallocatechin (L-EGC), D , L-gallocatechin (D, L-GC), L-epicatechin gallate (L-ECG), L-catechin ester (L-CG), L-epigallocatechin Gallate (L-EGCG), L-gallocatechin gallate (L-GCG). Because of the esterification of catechin and gallic acid in CG, ECG, GCG, and EGCG, they are called ester catechins; while C, EC, GC, and EGC that have not undergone esterification are called non-esterified. Ester catechins, the structure of each catechin is relatively similar, some are isomers, the main difference in st...

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.

[0021] (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

[0023] (3) Toxic solvent residue

[0024] 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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