Gallic acid (GA) application and production method

Gallic acid (GA), also known as gallic acid, is a natural product chemical constituent, chemically named 3,4,5-trihydroxybenzoic acid, with high medicinal value. It is widely found in rhubarb, eucalyptus, dogwood, celandine, mulberry, incense tree, tallow, pomegranate, yellow grass, arabian acacia and other plants. It is a kind of polyphenolic compound that exists in nature. Gallic acid, also known as gallic acid, double acid, chemical name 3,4,5-trihydroxybenzoic acid (CHO), is white or light yellow needle crystal or powder, usually in the form of monohydrate.

Application of gallic acid

1. Anti-tumor effect

1) Inhibit tumor formation: The formation of tumors is a multi-factor, multi-step, multi-gene mutation process. It is known that many chemical carcinogens can induce and promote tumor formation, and gallic acid has preventive and inhibitory effects on all stages of tumor formation. Gallic acid can inhibit the cancer-promoting effect of guanylate decarboxylase (ODC).

2) Cytotoxicity: Gallic acid can inhibit and directly kill tumor cells. When screening anti-tumor drugs by traditional Chinese medicine methods, it was found that GA showed cytotoxicity to primary cultured rat hepatocytes and macrophages when the IC was 4.8~13.2 ml.

3) Inhibition of tumor angiogenesis: Angiogenesis is a crucial pathological process in tumor growth and metastasis, and the activation, proliferation, migration and tubule formation of vascular endothelial cells (VEC) are the key steps. The study found that gallic acid inhibited the growth of tumor blood vessels due to synergistic or potent stimulatory effects between gallic acid and other unproven extracts, suggesting a natural and easily controlled dosing regimen, and also for the anti-VEC regeneration of gallic acid. Provide clinical evidence.

4) As a polyphenolic substance, GA has strong antioxidant and anti-free radical effects. Oxidative and free radical damage is recognized as one of the important mechanisms that cause cell DNA damage and then lead to cell malignancy.

5) Induction of tumor cell apoptosis: Research reports show that the sensitivity of GA to induce apoptosis does not change with cisplatin resistance, indicating that GA may be used in the treatment of lung cancer, especially lung cancer that is resistant to anti-tumor drugs

2. Effects on the liver

Chinese researchers believe that GA has the effect of anti-HBV. Anti-Hepatitis B Virus Surface Antigen (HBsAg) and Hepatitis B Virus e Antigen (HBeAg) were experimentally studied, using enzyme-linked immunosorbent assay (ELISA) technology to select 4 kinds of GA, Yunzhi Gantai, Yigan Granule and Yiganning Drug efficacy test.

Results The efficacy of anti-HBsAg was GA (4.86)>(better than) Yunzhi Gantai (5.53)>Yigan Granule (6.11)>Yiganning (6.66); the efficacy of anti-HBeAg was Yiganning (3.92)>Yigan Granules (4.87)>GA (5.48)> Yunzhihui (5.51); if the efficacy index is comprehensively evaluated, the order of anti-hepatitis B is GA (5.17)> Yiganning (5.29)> Yigan Granules (5.49)> Yunzhi Gantai (5.52). It can be seen that GA is an effective drug against HBsAg/HBeAg screened out in the laboratory.

3. Effects on blood vessels

The vascular effect of GA on the murine thoracic aorta was studied, and it was shown that GA had a vasoconstrictive effect on the constricted intact endothelial arteries treated with phenylephrine or prostaglandin F(2/ ), while GA had no vasoconstrictive effect on the naked endothelial arteries. . Pretreatment with N(G)-nitro-L-arginine methyl ester, an inhibitor of NO synthesis, abolished GA-induced vasoconstriction; pretreatment with indomethacin or BQ610 did not abrogate GA-induced vasoconstriction effect.

Pretreatment of endothelial-exposed arteries with GA significantly reduced acetylcholine-induced vasorelaxation, as well as that of nitroprusside. These results show a strong inhibitory effect on GA-induced endothelium-dependent contraction and relaxation of endothelium-dependent, but not endothelium-independent, relaxation.

4. Fight against AIDS

Gall tannins are esters of gallic acid and polyols such as glucose, quinic acid, shikimic acid, etc. Common types of gallic tannins are: tannins (Chinese gall tannins), turkey tannins and tara tannins. Gall tannins are often a mixture of esters with varying degrees of doubling. Gallotannin is one of the main varieties of tannins used in anti-HIV research.

5. Trypanicidal action

African trypanosomes are flagellate protozoan parasites that cause sleep disturbances in humans and animals. GA has potent insecticidal effect on both blood flow type and procirculation type trypanosomes, and the insecticidal effect depends on the number of trypanosomes: the LD50 value of GA for blood flow type is (46.96_+1.28)I*m, The LD50 of the anterior circulation type was (30.02_+3.49) m. The study on the mechanism of action of GA in killing trypanosomes showed that pretreatment with SOD and/or catalase could significantly reduce the trypanicidal effect induced by GA.

6. For anti-inflammatory, bacteriostatic and antiviral effects

The anti-inflammatory and antibacterial effects of gallic acid were studied, and it was shown that gallic acid has significant effects on the experimental rat joint swelling caused by egg white, dextran, 5-hydroxytryptamine, which represents acute inflammation, and formaldehyde, which represents chronic inflammation. Anti-inflammatory effect; take a certain amount of gallic acid, add water to grind and dissolve, and add it to 9ml agar medium.

Gallic acid has a strong inhibitory effect on Escherichia coli, Staphylococcus aureus, Pasteurella, and Streptococcus. The anti-NDV virus activity of functional component monomer gallic acid in Pu-erh tea was determined by cytopathic method. The results show that gallic acid has anti-NDV virus activity. The effect of gallic acid on the action of PPAK receptors was investigated using cell models. .

7. Hypoglycemic and lipid-lowering effects

The effect of gallic acid on amylase was studied by using hypoglycemic and lipid-lowering activity as the detection index. The results showed that gallic acid had a strong inhibitory effect on amylase.

Preparation method of gallic acid

The methods of extracting gallic acid from gallnuts include chemical method and biological method. The chemical method mainly includes acid hydrolysis method and alkaline hydrolysis method, and the biological method includes fermentation method and enzymatic method.

1. Chemical method

1) Acid hydrolysis method: The tannin aqueous solution is subjected to a homogeneous acid-catalyzed reaction with sulfuric acid as a catalyst under heating conditions.

A tannin molecule reacts with n water molecules, and under acidic conditions, it is heated and hydrolyzed to obtain a glucose (CHO) molecule and a gallic acid molecule.

2) Alkaline hydrolysis method

The tannin aqueous solution is hydrolyzed under alkaline conditions, and then neutralized and acidified by sichuan acid to generate gallic acid.

2. Biological method

1) Fermentation method: use microorganisms to ferment in an aqueous solution containing tannins, and use glucose in tannins as a carbon source for the growth and reproduction of microorganisms. Microorganisms are induced to produce biological enzymes to catalyze the hydrolysis of tannins. Technological process: galls are crushed and sieved - leached with water to obtain 30 tannin solution - added black mold seeds (separated and cultured on gall) - fermented for 8-9 days - filtered out of gallic acid precipitate - washed with water - crude gallic acid - dissolved in water One recrystallization and one finished product gallic acid

2) Enzymatic method: The key of enzymatic method is to screen and prepare high-efficiency biological enzymes. Tannase is an acetyl hydrolase, which belongs to the extraspore-induced acyl hydrolase. It can efficiently, specifically and directionally cleave the ester bond, depsibond bond and glycosidic bond in the tannin molecule to generate gallic acid. Under appropriate conditions, a variety of molds and inducer tannins can produce tannase.

The commonly used strain is Aspergillus niger. Technological process: Enzyme cultivation-fermentation to produce enzymes-(adding raw materials) hydrolysis to make acid-filtration-concentration-coarse crystallization-separation-decolorization-first-time crystallization-secondary crystallization-drying-pulverization-finished gallic acid.