Quercetin, also known as quercetin, quercetin, is soluble in glacial acetic acid. The alkaline aqueous solution is yellow and almost insoluble in water. The ethanol solution has a very bitter taste. It can be used as a medicine and has good expectorant and cough-relieving effects, and has a certain antiasthmatic effect. In addition, it has the effects of lowering blood pressure, enhancing capillary resistance, reducing capillary fragility, lowering blood lipids, dilating coronary arteries, and increasing coronary blood flow. For the treatment of chronic bronchitis. It also has an auxiliary therapeutic effect on patients with coronary heart disease and hypertension.

On October 27, 2017, the World Health Organization’s International Agency for Research on Cancer released a preliminary list of carcinogens for reference. Quercetin is included in the list of Category 3 carcinogens. Basic introduction Chinese name: Quercetin English name: Quercetin Alias: Quercetin Chemical formula: C15H10O7 Molecular weight: 302 Purity: 98 Mp: 313~314℃ Basic information, physical properties, antioxidant properties, toxicity, preparation method, quality indicators, application , safety terms, risk terms, plant sources, uses, preparation methods, research and development progress, anti-tumor effects, derivative research, basic information Quercetin english nameQuercetin Synonyms Quercetin, quercetin, Meletin, Sophretin. Chemical name 4H-1-Benzopyran-4-one, 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-Flavone Molecular formula and molecular weight C15H10O7: 302.23 Physicochemical properties of quercetin Yellow needle-like crystals, quercetin is a flavonoid Compounds mostly exist in the form of glycosides. Quercetin can be obtained by acid hydrolysis. Molecular formula C 15 H 10 O 7 Molecular weight 302 Mp 313~314℃ UVλmax258nm, 375nm (EtOH) Purity 98 Source exists in the flowers and leaves of many plants , in fruits, they mostly exist in the form of glycosides, such as rutin (rutin), quercetin, hyperoside and other plants with higher content. Physical properties: Dihydrate is yellow needle crystal (dilute ethanol), becomes anhydrous at 95-97°C, melting point is 314°C (decomposes). Soluble in cold ethanol (1:290), easily soluble in hot ethanol (1:23), soluble in methanol, ethyl acetate, glacial acetic acid, pyridine, acetone, etc., insoluble in water, benzene, ether, chloroform, petroleum Ether, etc., the alkaline aqueous solution is yellow and almost insoluble in water, and the ethanol solution tastes very bitter. Antioxidant properties: Quercetin is quercetin, which has a double bond between the 2 and 3 positions in its molecule and two hydroxyl groups at the 37 and 47 positions, so it can act as a free radical generated during metal chelation or oxidation of oils and other processes. The function of the receptor can be used as an antioxidant for fats and ascorbic acid. Toxicity No acceptable daily intake has been established. Preparation method: Grind oak bark into powder, wash with hot water, extract with dilute ammonia, and neutralize with dilute sulfuric acid. Boil the filtrate to precipitate crystals. Quality indicators There is currently no standard for quercetin used as a food additive. Application In addition to being used as food antioxidant, it can also be used as edible yellow pigment. Safety Terms 1. After accidental contact with skin, rinse immediately with plenty of soap and water. 2. If you have an accident or feel unwell, seek medical attention immediately (show the label if possible). Risk terms 1. Toxic if swallowed. Plant sources: Fagaceae plant Quercus iberica bark and leaves, Berberidaceae plant Dyso *** a veitchii (Hemsl. et Wils.) Fu, Hypericaceae plant Red Eclipta (Forsythia hunanensis) ) Hypericum ascyron L. Whole plant, Apocynaceae plant Apocynum lancifolium Rus. Leaves. Function and use: This product has good expectorant and cough-relieving effects, and has a certain anti-asthmatic effect. The oral LD50 for mice is 160mg/kg. Purpose: Antioxidant.

Mainly used in oils, beverages, cold drinks, and meat processing products. Use 2: A natural dye. Can be used as a medium dye. For wool and cotton, aluminum salts are used to obtain yellow, chromium salts are used to obtain olive yellow, tin salts are used to obtain orange, and iron salts are used to obtain olive green. The soap resistance is very good and the light resistance is moderate. Preparation method 1. Recovery of isoquercetin from bioflavonoids 2. Preparation method of quercetin and isoquercetin derivatives 3. Quercetin derivatives and their medicinal uses 4. Preparation of isoquercetin by enzymatic hydrolysis of rutin Methods of quercetin and quercetin 5. Research and development progress of a method for extracting quercetin-7-O-rhamnoside. Anti-tumor effect Quercetin can significantly inhibit the effect of cancer-promoting agents and inhibit the growth of malignant cells in vitro. Growth and inhibition of DNA, RNA and protein synthesis in Ehrlich ascites cancer cells. Quercetin inhibits platelet aggregation and the release of 5-hydroxytryptamine (5-HT). Quercetin has a significant inhibitory effect on platelet aggregation induced by ADP, thrombin and platelet activating factor (PAF), among which PAF has the strongest inhibitory effect. Quercetin can also significantly inhibit thrombin-induced platelet aggregation in rabbits 3H-5 -HT release. Research on Quercetin Derivatives Quercetin is insoluble in water, so hydrophilic groups are introduced to increase solubility and facilitate absorption, thus enhancing its pharmacological effects. Synthetic quercetin oxyacetate lysine salt has increased water solubility. Clinical trials have proven that it has high efficacy in treating bleeding disorders, circulatory disorders, atherosclerosis, etc. In addition, Dr. Xing's article "The discovery of using quercetin to block androgen on hormone-dependent human prostate cancer cells" believes that quercetin can block the effect of androgens on hormone-dependent human prostate cancer cells. When the effects of androgens are blocked, the growth of prostate cancer cells is slowed or stopped. Onions, apples, red wine, and green tea contain a large amount of quercetin, and patients with prostate cancer can eat more of them. Quercetin According to an interview with Dr. Xing Nianzang on the CCTV Science and Education Channel, in the United States, quercetin is an over-the-counter drug for treating prostate cancer and can be purchased in pharmacies. But in China, the drug has not been approved as a prostate treatment drug. Standard product name: Quercetin English name: Quercetin CAS NO: 117-39-5 Product alias: Quercetin, 3,3',4',5,7-pentahydroxyflavone, 2-(3,4-di Hydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one, 3,3',4',5,7-Pentahydroxyflavonelt; brgt; 2-(3,4- Dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one, quercetin Cas number: 117-39-5 MDL: MFCD00149487 Beilstein: 317313 Molecular formula: C15H10O7 Molecular weight: 302.24 Specification: 98 Detection method: HPLC Product shape: yellow needle crystal Physical properties: decomposition temperature 314°C, very slightly soluble in ether, insoluble in cold water, hardly soluble in hot water, soluble in glacial acetic acid and alkaline aqueous solution, showing yellow color, etc. Pharmacological effects: Quercetin has good expectorant and cough-relieving effects, and has a certain antiasthmatic effect, and is used to treat chronic bronchitis. In addition, it has the effects of lowering blood pressure, enhancing capillary resistance, reducing capillary fragility, lowering blood lipids, dilating coronary arteries, increasing coronary blood flow, etc. It has auxiliary therapeutic effects on patients with coronary heart disease and hypertension. Product source: Sophora japonica, a leguminous plant. (Sophora flavescens Ait.) dry flower bud 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)