What is Quercetin?

Quercetin, also known as Quercetin, Quercetin, is soluble in glacial acetic acid, the alkaline aqueous solution is yellow, almost insoluble in water, and the ethanol solution tastes bitter. It can be used as medicine, which has good expectorant and antitussive effects, and has certain antiasthmatic effects. In addition, it also reduces blood pressure, enhances capillary resistance, reduces capillary fragility, lowers blood lipids, expands coronary arteries, and increases coronary blood flow. For the treatment of chronic bronchitis. It also has adjuvant treatment for patients with coronary heart disease and hypertension.

On October 27, 2017, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization initially compiled the reference. Quercetin was in the list of 3 types of carcinogens. ^[1]

Chinese name: Quercetin
English name: Quercetin
nickname: Quercus

Chemical formula: C15H10O7
Molecular weight: 302
Purity: 98%
M p: 313 ~ 314

Quercetin Basic Information

Quercetin

[English name] Quercetin

[Synonym] Quercetin, Quercetin, Meletin, Sophretin.

[Chemical name] 4H-1-Benzopyran-4-one, 2- (3,4-dihydroxyphenyl) -3,5,7-trihydroxy-Flavone

Quercetin [Molecular formula and molecular weight] C15H10O7: 302.23

[Physicochemical properties] Yellow needle-like crystals, quercetin is a flavonoid compound, mostly in the form of glycosides, can be obtained by acid hydrolysis.

[Molecular formula] C ₁₅ H ₁₀ O ₇

[Molecular weight] 302

[Mp] 313 ~ 314

UV max258nm, 375nm (EtOH)

[Purity] 98%

[Source] It exists in the flowers, leaves and fruits of many plants, and mostly exists in the form of glycosides, such as rutin (rutin), quercetin, hypericin and other plants.

Physical properties of quercetin

The dihydrate is yellow needle-like crystals (dilute ethanol), becomes anhydrous at 95-97 ° C, and has a melting point of 314 ° C (decomposed). Soluble in cold ethanol (1: 290), easily soluble in hot ethanol (1:23), soluble in methanol, ethyl acetate, glacial acetic acid, pyridine, acetone, etc. Ether, alkaline aqueous solution is yellow, almost insoluble in water, and ethanol solution tastes bitter.

Antioxidant properties of quercetin

Quercetin is a quercetin, which has a double bond between the 2 and 3 positions and 2 hydroxyl groups at the 37 and 47 positions, so it can be used as a free radical acceptor generated during metal chelation or oxidation of lipids. Function, can be used as an antioxidant for oil and ascorbic acid ^[2] .

Quercetin toxicity

No allowable daily intake is specified.

Quercetin method

The oak bark was ground into powder, washed with hot water, extracted with dilute ammonia, and then neutralized with dilute sulfuric acid. Boiling strainer

Liquid, crystals were precipitated to obtain ^[2] .

Quercetin Quality Index

There is currently no quercetin standard for food additives.

Quercetin application

In addition to being used for food antioxidants, it can also be used as edible yellow pigment ^[2] .

Quercetin safety term

1. Immediately after contact with the skin, rinse with plenty of soap and water.

2. In case of accident or discomfort, consult a doctor immediately (show the label if possible).

Quercetin risk term

1. Toxic if swallowed.

Quercetin plant source

Bark and Quercus iberica Quercus iberica bark and leaves, Berberid red hydrangea Dysosma veitchii (Hemsl. Et Wils.) Fu, hypericum plant Hydracum ascyron L. whole Grass, Apocynum lancifolium Rus.

Use of quercetin

This product has good expectorant and antitussive effects, and has a certain antiasthmatic effect ^[3] . The oral LD50 of the mice was 160 mg / kg.

[Use one] antioxidant. Mainly used in oils, beverages, cold drinks, and processed meat products.

[Use two] A natural dye. Can be used as a media dye. For wool and cotton, yellow with aluminum salt, olive yellow with chrome salt, orange with tin salt, and olive green with iron salt. Soap resistance is very good, light resistance is medium.

Preparation method of quercetin

1. Recovery of isoquercetin from bioflavonoids

2. Preparation method of quercetin and isoquercetin derivatives

3. Quercetin derivatives and their medical uses

4. Enzymatic hydrolysis of rutin to prepare isoquercetin and quercetin

5. Extraction method of quercetin-7-O-rhamnoside

Research progress of quercetin

Antitumor effect of quercetin

Quercetin can significantly inhibit the effects of cancer-promoting agents, inhibit the growth of malignant cells in vitro, and inhibit DNA, RNA, and protein synthesis of Ehrlich ascites cancer cells.

Quercetin Quercetin can inhibit platelet aggregation and serotonin (5-HT) release. Quercetin significantly inhibits platelet aggregation induced by ADP, thrombin, and platelet activating factor (PAF). Among them, PAF has the strongest inhibitory effect. Quercetin can also significantly inhibit thrombin-induced rabbit platelets 3H-5 -HT release.

Studies on Quercetin Derivatives

Quercetin is insoluble in water, so the introduction of hydrophilic groups increases solubility and facilitates absorption, thereby enhancing its pharmacological effect. Synthetic quercetin oxyacetic acid lysine salt with increased water solubility. It has been proved by clinical trials that it has a high curative effect for the treatment of hemorrhagic diseases, circulatory disorders, and atherosclerosis.

In addition, Dr. Xing's article on "The discovery of quercetin to block androgen on hormone-dependent human prostate cancer cells" concluded that quercetin can block the effect of androgen on hormone-dependent human prostate cancer cells. Androgen effects are blocked

Quercetin After that, the growth of prostate cancer cells is delayed or stopped. Onions, apples, red wine, and green tea contain a large amount of quercetin, which can be eaten by patients with prostate cancer.

According to CCTV's interview with Dr. Xing Nianzeng, in the United States, quercetin is an over-the-counter drug for prostate cancer and can be bought in pharmacies. But in China, the drug has not yet been approved as a prostate treatment.

Standard

Product Name: Quercetin

English name: Quercetin

CAS NO: 117-39-5

Product aliases: Quercetin, 3,3 ', 4', 5,7-pentahydroxyflavones, 2- (3,4-dihydroxyphenyl) -3,5,7-trihydroxy-4H-1-benzo Pyran-4-one, 3,3 ', 4', 5,7-Pentahydroxyflavone <br> 2- (3,4-Dihydroxyphenyl) -3,5,7-trihydroxy-4H-chromen-4-one, Mist Lutein

Cas number: [117-39-5]

MDL: MFCD00149487

Beilstein: 317313

Molecular formula: C15H10O7

Molecular weight: 302.24

Specification content: 98%

Detection method: HPLC

Product shape: yellow needle crystal

Physical properties: Decomposition temperature is 314 . It is slightly soluble in ether, insoluble in cold water, hardly soluble in hot water, soluble in glacial acetic acid and alkaline aqueous solution, etc.

Pharmacological effect: Quercetin has good expectorant and antitussive effects, and has a certain asthma effect, which is used to treat chronic bronchitis. In addition, it has the effects of reducing blood pressure, enhancing capillary resistance, reducing capillary fragility, lowering blood lipids, expanding coronary arteries, and increasing coronary blood flow. It has an adjuvant therapeutic effect on patients with coronary heart disease and hypertension.

Product source: Dried flower buds of Sophora flavescens Ait.

Production process: mainly completed by alcohol extraction, extraction, chromatography, crystallization and other processes

Storage method: cool and dry, protected from light and high temperature

Shelf life: 2 years (tentative)