Name | Gallic acid |
Synonyms | BETZ 0276 GALLIC ACID Gallic acid Gallic acid 0 GALLIC ACID-1-HYDRATE Gallic Acid Anhydrous Gallic acid(anhydrous) Pyrogallol-5-carboxylic acid 3,4,5-Trihydroxybenzoic acid Gallic acid, 5-Carboxybenzene-1,2,3-triol |
CAS | 149-91-7 |
EINECS | 205-749-9 |
InChI | InChI=1/C7H6O5/c8-4-1-3(7(11)12)2-5(9)6(4)10/h1-2,8-10H,(H,11,12) |
InChIKey | LNTHITQWFMADLM-UHFFFAOYSA-N |
Molecular Formula | C7H6O5 |
Molar Mass | 170.12 |
Density | 1.694 |
Melting Point | 251 °C (dec.) (lit.) |
Boling Point | 259.73°C (rough estimate) |
Flash Point | 271°C |
Water Solubility | 12 g/L cold water |
Solubility | Soluble in water, alcohol and ether. |
Vapor Presure | 0Pa at 25℃ |
Appearance | Needle crystals (anhydrous methanol or chloroform) |
Color | Off-white |
Merck | 14,4345 |
BRN | 2050274 |
pKa | 4.41(at 25℃) |
PH | 3.75(1 mM solution);3.22(10 mM solution);2.71(100 mM solution) |
Storage Condition | 2-8°C |
Stability | Stability Stable, but may discolour upon exposure to light. Hygroscopic. Incompatible with strong oxidizing agents, strong bases, acid chlorides, acid anhydrides. |
Sensitive | `sensitive` to light and humidity |
Refractive Index | 1.5690 (estimate) |
MDL | MFCD00002510 |
Physical and Chemical Properties | Needle Crystal (from anhydrous methanol and chloroform crystallization),210 ° C sublimation, to obtain a stable crystal, 258~265 ° C (decomposition) and an unstable crystal, the melting point was 225-230 °c. Density 1.694g/cm3(60 C). Loss of water of crystallization at 100-120 ℃. 1G dissolved in 87ml water, 3ml boiling water, 6ml ethanol, 100ml ether, 10ml glycerol, 5ml acetone. Insoluble in benzene, chloroform, petroleum ether. |
Use | Has antibacterial effect, can treat bacillary dysentery. With convergence, hemostasis, antidiarrheal effect. Can be used as a preservative. Pyrogallic acid, pharmaceuticals, inks, mordant dyes and anti-explosion agents can be prepared. They are also used as developers and Analytical reagents for the detection of free mineral acids, dihydroxyacetone, alkaloids and metals. |
Hazard Symbols | Xi - Irritant |
Risk Codes | 36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S24/25 - Avoid contact with skin and eyes. S37/39 - Wear suitable gloves and eye/face protection |
WGK Germany | 2 |
RTECS | LW7525000 |
FLUKA BRAND F CODES | 8-9-23 |
TSCA | Yes |
HS Code | 29182900 |
Toxicity | LD50 in rabbits (g/kg): 5.0 orally (Dollahite) |
gallic acid, which usually contains one water of crystallization, is a white or pale yellow needle-like crystal. Molecular weight 170. 12, relative density of 1.694, melting point 235~240 ℃ (decomposition). Heating to 100~120 deg C can lose the water of crystallization, heating to 200 deg C above can be decarboxylated into pyrogallic acid (namely pyrogallol). Soluble in hot water, alkaline aqueous solution, ether, ethanol, acetone and glycerol, insoluble in cold water, insoluble in benzene and chloroform. Long-term storage in the air due to oxidation and color deepening, with the characteristics of the enol compound, the case of ferric ions will produce blue purple.
gallic acid is usually prepared by decomposition of tannic acid.
This product is 3 ,4, 5-trihydroxybenzoic acid monohydrate. Calculated as the dried product, the content of C7H60 5 should be 98. 0% ~ 102. 0%.
In the pharmaceutical, food, light industry have a wide range of applications. For example, iron gallate is the basic raw material for the production of blue-black ink, gallic acid is a hemostatic astringent, and the addition of Gallic acid to edible oils can increase the storage time and oxidation resistance of oils and fats.
take 0.10g of this product, add of water to dissolve it, and then determine it according to law (General rule 0631). The p H value should be 3 .0~3. 8.
take this product l .O g, add anhydrous ethanol 20ml to dissolve, and check according to law (general rule (J901 and general rule 0902), the solution should be clear and colorless; If color, comparison with the yellow No. 3 Standard Colorimetric solution (General rule 0901 first method), should not be deeper.
take l . O g of this product and add 20 m l of water higher than 8 0°C to dissolve. Observe immediately and the solution should be clear.
take this product l.O g, after dissolving 20ml of heated water, cool to the crystallization of Gallic acid in a refrigerator (0~5°C), and immediately filter, the filtrate was added with 1% gelatin and sodium chloride solution (freshly prepared. Take 0.5g of gelatin, 5g of sodium chloride, dissolve in 50ml of water with a temperature of not more than 60 ° C, then get) 5~6 drops, the solution should be clear.
take 2.0g of this product, put it in a 100ml measuring flask, Heat 90ml of water to dissolve, let it cool to room temperature, dilute it to the scale with water, shake it well, and put it in the refrigerator (0~5°C). After cooling to the crystallization of gallic acid, it was immediately filtered and the filtrate was taken out. 0 m l, check according to law (General Rule 0 8 0 1 ) , and standard sodium chloride solution 5.0ml of the control solution prepared by the same method should not be more concentrated (0.01%).
Take 2 5.0 m l of the filtrate under the chloride examination item, put it in a 50 m l Nessler Cuvette, and add hydrochloric acid solution (2 -3)0. 3 m l, ethanol 3 m l, 10% barium chloride solution lm l, shake, place for 10 minutes, check according to law (General rule 0802), compared with the standard potassium sulfate solution 2.5 m l, the control solution prepared by the same method should not be deeper (0.05).
take this product, dry to constant weight at 105°C, weight loss shall not exceed 10.0% (General rule 0831).
Take 2. 0g of this product, burn to constant weight at 550~600°C (General Rule 0 8 4 1 ) , and the residue shall not exceed 0 .1%.
take 2.0g of this product, place it in the crucible, slowly cauterize until complete carbonization, and let it cool; Add sulfuric acid 0. The residue was moistened at 5M l, heated at low temperature until the sulfuric acid vapor was removed, and then burned at 50-50-C to completely Ash and cool, the residue was dissolved by adding 5m l of dilute hydrochloric acid and 10ml of water, heated in a water bath, allowed to cool and filtered. The Crucible and filter were washed with an appropriate amount of water, after dilution with water to make 35ml, add ammonium persulfate 50mg, check according to law (General rule 0807), and standard iron solution 2.0 M l compared with the control solution made by the same method, not deeper (0. 001%).
The residue left under the item of taking the ignition residue shall not contain more than 10 parts per million of heavy metal when examined by law (General Principles 0821, Law II).
measured by high performance liquid chromatography (General 0512).
pharmaceutical excipients, chelating agents and antioxidants.
sealed and stored in a dry place.
Plant source: | Tea |
LogP | 0.7 |
NIST chemical information | Information provided by: webbook.nist.gov (external link) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
Introduction | Gallic acid (GA) is a component of hydrolyzable tannin, also known as gallic acid, chemical name 3,4, 5-trihydroxybenzoic acid. The content of gallic acid in Yunnan Pu'er tea is relatively high, and it has many biological effects such as antibacterial, anti-inflammatory, anti-tumor, and anti-mutation. |
physiological activity | gallic acid itself has significant antioxidant effect, and also has many effects such as anti-tumor, trypanosomiasis, liver protection and anti-hepatitis B virus. Recent studies have pointed out that gallic acid may be one of the effective components of Pu 'er tea to inhibit cholesterol synthesis by HepG2 cell lines. On the whole, the content of gallic acid (9.01 mg/g) in Pu 'er tea is higher than that of other traditional Chinese medicinal materials. In this sense, gallic acid is one of the important physiological active components of Pu 'er tea. |
uses | gallic acid has many uses in pharmacy, ink, dye, food, light industry and organic synthesis. Gallic acid and ferric ions form blue-black precipitate, which is the raw material of blue-black ink; it is also used in industry for leather making; it can also be used as a photographic developer. Propyl gallate is an antioxidant, which can be used for edible fats to prevent spoilage. In medicine, gallic acid is a hemostatic astringent and a mild local stimulant. It has antibacterial effect and can treat bacillary dysentery. It has astringent, hemostatic and antidiarrheal effects. Can be used as a preservative. It can prepare pyrogallic acid, drugs, inks, mordant dyes and anti-explosion agents. It is also used as a developer and an analytical reagent for detecting free inorganic acids, dihydroxyacetone, alkaloids and metals. It can be used as a preservative, can prepare mordant dyes and anti-explosion agents, etc. Used as a chemical reagent Mainly used as a color-forming agent for blue and black inks. The pharmaceutical industry is used to prepare sulfanilamide synergistic drug TMP and as a compounding agent for sulfanilamide drugs such as SMZ and SD. The food industry is used to prepare the preservative propyl gallate. The defense industry is used to prepare anti-explosion agents. In addition, it can also be used for the production of mordant dyes and as a developer, etc. used as a depolarization agent in electrochemical analysis; used for reducing phosphomolybdic acid; used for the verification of antimony, barium, bismuth, calcium, Cerium and copper, etc.; used for the determination of phosphorus, nitrite, silver, thorium and titanium, etc. A water-soluble phenolic acid that exists in the leaves of grapes and many plants and is an effective in vitro antioxidant. |
production method | made from gallnut. The main component of gallnut is tannic acid, which belongs to hydrolyzed tannin, which can be dissolved in hot water and has astringent taste. It is an amorphous complex organic matter. Chinese gallnut tannic acid is a complex mixture formed by the combination of gallic acid, double acid and glucose in the form of glycosides or esters. Tannic acid is hydrolyzed under pressure to produce gallic acid and glucose. When hydrolyzing, gallate is first generated, and then gallic acid is hydrolyzed from bisgallate. The hydrolysis temperature is 133-135 ℃, and the pressure is 0.18-0.2MPa. From the pressure increase to 0.18MPa, the reaction is maintained for 2h to reach the end point. Compared with normal pressure hydrolysis, sulfuric acid and steam can be saved, and the production capacity can increase 25%. |
category | toxic substances |
toxicity classification | poisoning |
acute toxicity | vein-mouse LD50: 320 mg/kg |
flammability hazard characteristics | combustible, spicy and irritating smoke from the fire site |
storage and transportation characteristics | warehouse low temperature, ventilation, drying |
fire extinguishing agent | water, carbon dioxide, dry powder, sand |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |