Preparation method of methylated EGCG (Epigallocatechin Gallate)

A technology of methylation and preparation of liquid phase, which is applied in the field of preparation of methylated EGCG, can solve the problems of high recurrence rate, large side effects, and single action link of western medicine, and achieve the effect of good process stability

Active Publication Date: 2014-06-18
HUNAN AGRICULTURAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, most of the drugs used to treat allergic diseases are chemical synthetic drugs, such as allergy mediator release agents, antihistamines, hormone drugs, etc. These chemical synthetic drugs have large side effects and high prices
Due to changes in the living environment, the number of allergic patients has increased sharply. However, the treatment of allergic diseases requires long-term persistence. It is hoped that the development of food or health products that have no side effects on the human body can alleviate allergic symptoms. Natural anti-allergic drugs or health products with low toxicity and side effects. This measure has become an important research direction for the development of new natural anti-allergic drugs and health foods in the world. It avoids the high recurrence rate of western medicine, does not remove the root, has a single action link, and has adverse reactions. and other shortcomings

Method used

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  • Preparation method of methylated EGCG (Epigallocatechin Gallate)
  • Preparation method of methylated EGCG (Epigallocatechin Gallate)
  • Preparation method of methylated EGCG (Epigallocatechin Gallate)

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Weigh 95% of EGCG7.33g, K 2 CO 3 22.11g, add 800mL of acetone solution and 4mL of dimethyl sulfate (density 1.333g / mL) respectively, flush into nitrogen, ultrasonically sonicate for 2 hours, filter, concentrate in vacuo, add 350mL ethyl acetate to extract twice, concentrate and freeze-dry, 4.94 g of the crude methylated EGCG product synthesized was obtained.

[0032] The crude product was dissolved in methanol, filtered through a 0.45 μm filter membrane, and subjected to preparative high-performance liquid chromatography, using the following preparative chromatographic conditions: Shimadzu PRC-ODS C 18Reversed-phase chromatographic column with an inner diameter of 20mm and a length of 250mm; the mobile phase is acetonitrile-water solution, and the gradient elution program is: 0-21min, the B pump maintains 15% acetonitrile, 21-23min, 15%B linearly increases to 20%B, and maintains After 7 minutes, it will drop to 15% B within 2 minutes; the flow rate is 15mL / min; the de...

Embodiment 2

[0035] Weigh 13.75g of 95% EGCG and 1.45g of K2CO3, add 1500mL of acetone solution and 7.5mL of dimethyl sulfate (density 1.333g / mL) respectively, flush into nitrogen, ultrasonicate for 3 hours, filter, concentrate in vacuo, add 500mL Extracted twice with ethyl acetate, concentrated and freeze-dried to obtain 9.31 g of the synthesized methylated EGCG crude product.

[0036] The crude product was dissolved in methanol, filtered through a 0.45 μm filter membrane, and subjected to preparative high-performance liquid chromatography, using the following preparative chromatographic conditions: Shimadzu PRC-ODS C 18 Reverse-phase chromatographic column, inner diameter 30mm, length 250mm; mobile phase is acetonitrile-water solution, gradient elution program: 0~21min, B pump maintains 15% acetonitrile, 21~23min, 15%B linearly increases to 20%B, maintains After 7 minutes, it will drop to 15% B within 2 minutes; the flow rate is 40mL / min; the detection wavelength is 265nm; the column tem...

Embodiment 3

[0039] Weigh 95% of EGCG22.92g, K 2 CO 3 69.1g, add 3000mL of acetone solution and 12.5mL of dimethyl sulfate (density 1.333g / mL) respectively, flush into nitrogen, ultrasonically sonicate for 5 hours, filter, concentrate in vacuo, add 800mL ethyl acetate to extract twice, concentrate and freeze-dry , to obtain 15.41 g of synthetic methylated EGCG crude product.

[0040] The crude product was dissolved in methanol, filtered through a 0.45 μm filter membrane, and subjected to preparative high-performance liquid chromatography, using the following preparative chromatographic conditions: Shimadzu PRC-ODS C 18 Reversed-phase chromatographic column with an inner diameter of 50mm and a length of 250mm; the mobile phase is acetonitrile-water solution, and the gradient elution program is: 0-21min, the B pump maintains acetonitrile at 15%, 21-23min, 15%B linearly increases to 20%B, and maintains After 7 minutes, it will drop to 15% B within 2 minutes; the flow rate is 100mL / min; the ...

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Abstract

The invention provides a method for separating and preparing a chemosynthetic methylated EGCG (Epigallocatechin Gallate) rough product by utilizing a method which combines supercritical fluid chromatography with reversed-phase high-performance liquid chromatography. The method comprises the steps of synthesizing methylated EGCG by taking dimethyl sulfate as a methylated reagent and adopting a chemical method; further separating and preparing the chemosynthetic rough product by utilizing the reversed-phase high-performance liquid chromatography and the supercritical fluid chromatography to obtain three methylated EGCG monomers, namely EGCG4'Me.3', 4'-di-O-methyl-EGCG and 4',4-di-O-methyl-EGCG. According to the method, the purity of a product achieves more than 97%.

Description

technical field [0001] The invention relates to the field of compound preparation, in particular to a method for preparing methylated EGCG. Background technique [0002] In the late 1990s, Japanese researchers were the first to successfully isolate and identify two new catechin derivatives with anti-allergic function from Taiwan Dongding Oolong. The molecular structure is (-)-epigallocatechin- 3-O(4-O-methyl)gallate (EGCG4″Me) and (-)-epigallocatechin-3-O(3-O-methyl)gallate (EGCG3″Me). Following the emergence of these two methylated EGCGs, more in-depth studies were conducted on the chemical synthesis of methylated EGCG, enzymatic synthesis, and metabolites of EGCG in mice and humans, and more methylated EGCG, but the current research on the pharmacological efficacy of methylated EGCG mainly focuses on EGCG4″Me and EGCG3″Me. [0003] Allergic diseases are a common disease with a high incidence rate, which can seriously affect the quality of life, work and study of patients...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C07D311/62
CPCC07D311/62Y02P20/54
Inventor李银花刘仲华李娟黄建安李适王英姿
OwnerHUNAN AGRICULTURAL UNIV