L-Epicatechin is an important natural polyphenol, which is widely used in the fields of food, cosmetics, health products and medicines. As a flavonoid, epicatechin has many physiological activities, such as anti-oxidation, lowering blood sugar, preventing cardiovascular diseases, anti-inflammation, protecting nerves, and inhibiting bacteria.
Anti-oxidize effect:
When the concentration of free radicals in the body is too high, the risk of disease will increase. The antioxidant activity of epicatechin is considered to be the ability to capture chain-carrying free radicals by providing phenolic hydrogen atoms in the A ring and B ring, due to the presence of phenolic hydroxyl groups in the molecular structure of epicatechin, especially the phthalate The ortho hydroxyl group in phenol or pyrogallol is easily oxidized into an aldehyde structure, which makes it have a strong ability to capture free radicals such as active oxygen, so it has the function of efficiently scavenging free radicals and lipid free radicals.
Lowering blood sugar and lowering insulin resistance:
Obese individuals often induce the occurrence of chronic diseases such as diabetes. BETTAIEB et al. found that adding epicatechin at a dose of 20 mg/kg body weight to the diet of adult rats fed a high-fructose diet can reduce the damage of the insulin signaling cascade (IR, IRK-1, Akt, ERK1/2), and at the same time Reduced upregulation of negative regulators (PKC, IKK, JNK, and PTP1B) in rat adipose tissue and suggested that epicatechin attenuates insulin resistance through its redox-regulated mechanism.
Prevent Cardiovascular Disease:
Compared with the control group of mice fed a high-cholesterol diet, the atherosclerotic lesion area of the mice in the epicatechin-added group was reduced by 27%, and at the same time inhibited the formation of plasma SAA and human-CRP induced by the diet, and had a significant effect on plasma Lipids had no effect, while the anti-atherogenic effect of epicatechin was specific to severe injury types and had little effect on mild injuries, suggesting that epicatechin tends to alleviate severe cardiovascular lesion types.
At present, the production of L-Epicatechin mainly relies on chemical synthesis and biosynthesis. This article will detail both approaches and their associated advantages and disadvantages.
Part I: Chemical Synthesis
Chemical synthesis is a method of synthesizing some simple compounds into target substances through chemical reactions. In the chemical synthesis of L-Epicatechin, the raw materials used are usually substances such as styrene, formaldehyde, soybean or red wine. Three commonly used chemical synthesis methods of L-Epicatechin will be introduced in detail below.
Method 1: Krafur reaction:
The Clafoor reaction is a method for the synthesis of aromatic rings from aldehydes and aromatic hydrocarbons. In this reaction, styrene and formaldehyde can be used to synthesize the transition compound 2-phenyl-3,4-dihydroxypentanone, and L-Epicatechin can be obtained after acid catalysis and dehydration reaction.
The advantage of this method is that the raw materials are easy to obtain, the reaction process is simple, and the reaction yield is as high as 54%. But its disadvantage is that it needs a strong acid catalyst, and a large amount of waste gas and waste liquid will be generated in the reaction.
Method 2: imine reaction:
The imine reaction is a method of synthesizing imines by reacting amines and aldehydes, and then reacting imines and aromatic hydrocarbons under acidic conditions to synthesize aromatic rings. In the method, styrene and formaldehyde can be synthesized into imines, and then reacted with karlene substances to obtain L-Epicatechin.
The method has the advantages of simple reaction process, high product purity and high reaction yield of more than 80%. But its disadvantage is that it needs to use high-purity karlene substances, and there are many reaction by-products.
Method 3: Metadianhydride reaction:
Metadianhydride reaction is a method to obtain aromatic compounds through acid-catalyzed ring synthesis. In the method, the side chain structures in styrene and paclitaxel can be simultaneously reacted to synthesize a functional hydroxybenzyl intermediate through an acid-catalyzed ring, and finally L-Epicatechin can be obtained through a reduction reaction.
The advantage of this method is that the obtained intermediate has high stability, is easy to handle, and the reaction yield is about 40%. But its disadvantage is that the cost of raw materials is higher and the reaction steps are more.
Part II: Biosynthesis
Biosynthesis is a method of synthesizing simple compounds into target substances by biological means. The biosynthesis of L-Epicatechin mainly comes from the fermentation method in the production process of food additives. Two commonly used biosynthesis methods are described in detail below.
Method 1: Microbial fermentation method:
Microbial fermentation is a method that uses microorganisms (such as yeast) to ferment and prepare target substances. The method can utilize the isoflavone enzyme in the soybean to promote the cyclization reaction of the isoflavone derivatives to obtain L-Epicatechin. The reaction process is harmless and does not require any chemical reagents and catalysts. The method has the advantages of good reaction conditions, high reaction yield, high product purity and the like. But its disadvantage is that the reaction process takes a long time and cannot be produced quickly.
Method 2: Enzyme method:
Enzyme method is a method of using enzymes to catalyze the synthesis of target substances. The method can utilize polyphenol oxidase to catalyze catechin and its derivatives in one step to obtain L-Epicatechin. It has the characteristics of mild reaction conditions, no harm to the environment, and high purity of reaction products. But its disadvantage is that the reaction scale is limited by factors such as the choice of enzyme and the source of enzyme.
In summary, chemical synthesis and biosynthesis each have their advantages and disadvantages. The chemical synthesis method has the advantages of large production scale, simple operation, and high reaction yield, but its disadvantage is that some methods require the use of toxic and harmful substances, which have a certain impact on the environment and human health. The biosynthesis method has the advantages of green production process and high purity of reaction products, but its disadvantage is that the production scale is limited by factors such as enzyme source and screening. Therefore, for different production requirements, different synthesis methods can be selected.