117-39-5

Basic information

• Product Name: Quercetin
• Synonyms: 3,3',4',5,7-Pentahydroxyflavone 2-(3,4-Dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one;2-(3,4-DIHYDROXYPHENYL)-3,5,7-TRIHYDROXY-4H-1-BENZOPYRAN-4-ONE;3,3',4',5,6-PENTA-HYDROXY-FLAVONE;3,3',4',5,7-PENTAHYDROXYFLAVONE;AKOS NCG1-0081;MELETIN;FLAVIN MELETIN;LABOTEST-BB LT00455149
• CAS NO: 117-39-5
• Molecular Formula: C₁₅H₁₀O₇
• Molecular Weight: 302.24
• EINECS: 204-187-1
• Product Categories: Pharmaceutical Raw Materials;Miscellaneous Natural Products;Functional Products;Natural Plant Extract;Caspases/Apoptosis;reference substance;Plant extracts;Herb extract;chemical reagent;pharmaceutical intermediate;phytochemical;reference standards from Chinese medicinal herbs (TCM).;standardized herbal extract;natural product;Inhibitors
• Mol File: 117-39-5.mol
• Article Data: 169

Chemical Properties

• Melting Point: 314-317°C
• Boiling Point: 363.28°C (rough estimate)
• Flash Point: 248.1 ºC
• Appearance: Yellow to green yellow crystalline powde
• Density: 1.3616 (rough estimate)
• Refractive Index: 1.4790 (estimate)
• Storage Temp.: Store at 0-5°C
• Solubility: insoluble in H2O; ≥15.1 mg/mL in DMSO; ≥3.28 mg/mL in EtOH
• PKA: 6.31±0.40(Predicted)
• Water Solubility: <0.1 g/100 mL at 21 oC
• Merck: 13,8122
• BRN: 317313
• CAS DataBase Reference: Quercetin(CAS DataBase Reference)
• NIST Chemistry Reference: Quercetin(117-39-5)
• EPA Substance Registry System: Quercetin(117-39-5)

Safety Data

• Hazard Codes: T,Xi
• Statements: 25-36/37/38
• Safety Statements: 45-36-26
• RIDADR: 2811
• WGK Germany: 3
• RTECS: LK8750000
• HazardClass: 6.1(b)
• PackingGroup: III
• Hazardous Substances Data: 117-39-5(Hazardous Substances Data)

Usage

Expectorants

Quercetin is commonly used as a expectorant drug in clinical medicine in China. This product has various kinds of pharmacological functions such as having a good expectorant, cough effect, also having certain anti-asthma effect, and having further effects of lowering blood pressure, enhancing capillary resistance, reducing capillary fragility, reducing blood fat, expansion of coronary artery, increasing coronary blood flow. Clinically, quercetin is mainly used for treating clinical bronchitis and phlegmatic inflammation. It also has adjuvant therapy effect on coronary artery disease and high blood pressure. FDA may have some kinds of adverse reactions such as dry mouth, dizziness, and burning sensation in stomach area which may disappear after treatment. Quercetin is widely distributed in angiosperms such as Threevein Astere, Golden Saxifrage, berchemia lineata, gold, rhododendron dauricum, seguin loquat, purple rhododendron, Rhododendron micranthum, Japanese Ardisia Herb and Apocynum. It is a kind of aglycon which mainly combines with carbohydrate to be in the form of glycosides, such as quercetin, rutin, hyperoside.

Pharmacological effects

Quercetin can significantly inhibit the effect of cancer-promoting agent, inhibiting the growth of malignant cells in vitro, inhibiting the DNA, RNA, and protein synthesis of Ehrlich ascites tumor cells. Quercetin has effects of inhibiting the platelet aggregation and the release effect of serotonin (5-HT) as well as inhibiting the platelet aggregation process which is induced by ADP, thrombin and platelet-activating factor (PAF) in which having the strongest inhibition effect on PAF. Moreover, it can also inhibit thrombin-induced the release of platelet 3H-5-HT of rabbit. (1) Intravenously adding 0.5mmol/L quercetin (10ml/kg) drop wise can significantly shorten the duration of arrhythmia in mice of myocardial ischemia and reperfusion, reduce the incidence of ventricular fibrillation, and reduce the content of MDA as well as the activity of xanthine oxidase inside the ischemic myocardial tissue while having significantly protective effect on SOD. This may be related to the inhibition of the formation process of myocardial oxygen free radical and protection of SOD or directly scavenging of radical free oxygen in myocardial tissue. (2) Having in vitro assay with quercetin and rutin being together can disperse the platelet and thrombus adhered to the rabbit aorta endothelium with an EC50 of 80 and 500nmol/L, respectivly. In vitro assay of a concentration of quercetin at 50~500μmol/L has shown that it can improve cAMP level inside human platelet, enhance the PGI2-induced improvement of cAMP level of human platelet and inhibit the ADP-induced platelet aggregation. Quercetin at a concentration ranged from 2~50μmol/L has a concentration-dependent enhancement effect. Quercetin, at a concentration of 300 μmol/L in vitro can not only almost completely inhibit the process of platelet aggregation induced by platelet-activating factor (PAF), but also inhibit thrombin and ADP-induced platelet aggregation as well as inhibit the release of rabbit platelet 3H-5HT induced by thrombin; A concentration of 30 μmol/L can significantly reduce the liquidity of platelet membrane. (3) Quercetin, at a concentration at 4×10-5~1×10-1g/ml, has a inhibitory effect on the release of histamine and SRS-A in the lung of ovalbumin-sensitized guinea pig lung; A concentration of 1 × 10-5g/ml also has inhibitory effect on the for SRS-A induced ileum contraction of guinea pig. Quercetin, at a concentration of 5~50μmol/L, has a concentration-dependent inhibitory effect on the process of histamine release of human basophilic leucocyte. Its inhibitory effect on the ileum contraction of ovalbumin sensitized guinea pig is also concentration-dependent with an IC50 of 10μmol/L. A concentration in the range of 5×10-6~5×10-5mol L can inhibit the proliferation of cytotoxic T lymphocyte (CTL) as well as inhibit ConA-induced DNA synthesis. The above information is edited by the lookchem of Dai Xiongfeng.

Chemical Properties

Different sources of media describe the Chemical Properties of 117-39-5 differently. You can refer to the following data:
1. It is yellow needle-like crystalline powder. It has good thermal stability with the decomposition temperature being 314 °C. It can improve the light-tolerance property of food pigment for preventing the change of the flavor of food. Its color will change in case of metal ion. It is slightly soluble in water, soluble in an alkaline aqueous solution. Quercetin and its derivatives is a kind of flavonoid compound which are widely present in a variety of vegetables and fruits such as onions, sea buckthorn, hawthorn, locust, tea. It has effects of anti-free radical, anti-oxidation, anti-bacterial, anti-viral as well as anti-allergic. For application in lard, its various antioxidant indicators are similar with that of BHA or PG. Because of the double bond between the 2,3 position as well as the two hydroxyl groups in 3 ', 4' , it has application of being used as a metal chelate or being the receptor of the free groups produced during the oxidation process of grease. In this case, it can be used as the antioxidants of ascorbic acid or grease. It also has a diuretic effect.
2. Yellow to green yellow crystalline powde

Uses

Different sources of media describe the Uses of 117-39-5 differently. You can refer to the following data:
1. 1. It can be used as a kind of antioxidant which is mainly used for oil, drinks, cold drinks, meat processing products. 2. It has good effects of expectorant, anti-cough, anti-asthma and can be used for treating chronic bronchitis as well as for adjuvant therapy of coronary heart disease and high blood pressure. 3. It can also be used as analytical standards
2. Medicine, reported formation of epoxy resins on mixing with epichlorohydrin.
3. Quercetin has been used as an antioxidant which reversed the immunosuppressive effects of high glucose and hyperglycemic sera in type 2 diabetic patients.It has been used as a detoxifying phytochemical in Apis mellifera.It has been used as a positive control in DPPH (2,2- diphenyl-1-picryhydrazyl) radical scavenging assay. It has also been used for the preparation of calibration curve to determine total flavonoid content.

Production method

1. Crash the bark of trees in Fagaceae Quercus (Quercus) into powder, wash with hot brine, extract with dilute ammonia before neutralization with dilute sulfuric acid. Boil the filtrate and separate crystals. 2. It can be obtained by extracting Liliaceae onion (Alliumcepa) with 95% ethanol; it can also be produced from rutin (rutin) extract, quercetin, isoquercitrin, fennel glycosides, hyperoside, quercimeritrin, bloom glycosides through rutin degrading enzyme or hydrolysis with acidic aqueous solution.

Description

The name of quercetin has been used since 1857, which is derived from quercetum (oak forest) after Quercus. Quercetin is widely found in flowers, leaves, and fruits of various plants. Vegetables (such as onions, ginger, celery, etc.), fruits (such as apples, strawberries, etc.), beverages (such as tea, coffee, red wine, fruit juice, etc.), and more than 100 kinds of Chinese herbal medicines (such as Threevein Aster, mountain white chrysanthemum, Huai rice, Apocynum, Ginkgo biloba, etc.) contain this ingredient. Threevein Aster is a Chinese herbal medicine and used in Jiangxi province, China, for more than 30 years. Its plant name is three veins Mala, Compositae. It is rich in drug sources, which can be found in Southern provinces of China. Clinical practice proved that it has significant anti-inflammatory and expectorant effects, and it is a good prescription for the treatment of elderly chronic bronchitis.

Physical properties

Appearance: yellow needle-like crystalline powder. Solubility: slightly soluble in water; soluble in ethanol, acetone, pyridine, and acetic acid; easily soluble in ether and methanol. Melting point: 314–317 °C.

History

In 1936, Szent-Gyorgyi firstly reported the separation and identification of biological activity of quercetin. Usually quercetin is presented in the form of glycosides such as lutin, quercitrin, and mycoside, which can be hydrolyzed to get the quercetin. Quercetin has a polyphenol hydroxyl structure, which is of weak lipophilicity and poor hydrophilicity, resulting in its low bioavailability and limiting its clinical application. The synthesis of phenolic derivatives improves its bioavailability, which are lipid-soluble quercetin derivatives such as 3-O-methylquercetin, hydrophilic quercetin derivatives such as 3′-ON-carboxymethylformamide quercetin, and quercetin glycosides. Threevein Aster, having quercetin as one of the main active ingredients, has been used for the domestic clinical treatment for chronic bronchitis in China since 1971.

Indications

It is mainly used for the treatment of chronic bronchitis.

General Description

Yellow needles or yellow powder. Converts to anhydrous form at 203-207°F. Alcoholic solutions taste very bitter.

Air & Water Reactions

Sensitive to exposure to air and light. Insoluble in water.

Reactivity Profile

3,3',4',5,7-Pentahydroxyflavone is a strong antioxidant and a metal chelator. Promotes the formation of nitrosamines .

Hazard

Questionable carcinogen.

Health Hazard

ACUTE/CHRONIC HAZARDS: When heated to decomposition 3,3',4',5,7-Pentahydroxyflavone emits acrid smoke and irritating fumes.

Fire Hazard

Flash point data for 3,3',4',5,7-Pentahydroxyflavone are not available; however, 3,3',4',5,7-Pentahydroxyflavone is probably combustible.

Biological Activity

Anti-tumor agent; induces apoptosis and inhibits synthesis of heat shock proteins. Inhibits many enzyme systems including tyrosine protein kinase, phospholipase A 2 , phosphodiesterases, mitochondrial ATPase, PI 3-kinase and protein kinase C. Can also activate Ca 2+ and K + channels and behaves as an agonist at estrogen (GPR30) receptors.

Biochem/physiol Actions

Quercetin is a flavonoid with anticancer activity. Quercetin is a mitochondrial ATPase and phosphodiesterase inhibitor. It Inhibits PI3-kinase activity and slightly inhibits PIP kinase activity. Quercetin has antiproliferative effects on cancer cell lines, reduces cancer cell growth via type II estrogen receptors, and arrests human leukemic T cells in late G1 phase of the cell cycle. Quercetin may also inhibit fatty acid synthase activity.

Pharmacology

Experimental studies showed that quercetin had antitumor, anti-inflammatory, anti-oxidation, hypoglycemic, anti-obesity, antidepressant, and other effects. In vitro cell experiments and in vivo animal experiments have shown that quercetin could inhibit the growth of various malignant tumor cells such as human ovarian cancer, breast cancer, gastrointestinal tumor cells, and leukemia, and it could induce cancer cell apoptosis and had a reversal of tumor multidrug resistance (MDR) effect, while, combined with other anticancer drugs, it could enhance the effect of anticancer drugs. Quercetin could alleviate the inflammatory response that was aggravated by the activation of the central granulocytes. In the experimental study on the treatment of non-bacterial prostatitis and acute gouty arthritis, quercetin also showed a good anti-inflammatory effect. The experimental results showed that quercetin had a good direct scavenging effect on free radicals and exhibited antioxidant activity. In addition, it also had the anti-hepatic fibrosis, pulmonary fibrosis, keloid hyperplasia and glaucoma filtering bubble scarring and other effects, its mechanism involving the inhibition of fibroblast proliferation, inhibition of collagen synthesis, preventing oxidative damage and so on. Moreover, studies have shown that quercetin also had antibacterial, antiaging, antidepressant, antileukemia, antidiabetic, and other pharmacological effects.

Clinical Use

Since the first clinical phase I trial of quercetin in 1996 found that it had antitumor activity, quercetin has also been reported in early clinical trials of cardiovascular disease, diabetes, and other diseases. However, there is still insufficient evidence shown that quercetin has a significant effect on the treatment of the disease in clinic.The US FDA has issued a warning, emphasizing that quercetin is not a definite nutrient, unable to determine its content in the diet, nor can it be used as a drug. China’s Threevein Aster consists of a single Chinese herb, which was released by the Pharmacopoeia of the People’s Republic of China (1977) Part I. One of the main active ingredients obtained following the hydrolysis of Threevein Aster is quercetin, which has the function of relieving cough and eliminating phlegm and can be used for the treatment of chronic bronchitis. The anti-inflammatory effect of Threevein Aster is poor. Side effects after use include stomach discomfort, dizziness, and abdominal pain, while withdrawal can make them disappear.

Safety Profile

Poison by ingestion, subcutaneous, and intravenous routes. Experimental teratogenic and reproductive effects. Questionable carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data. Human mutation data reported. Used as a pharmaceutical and veterinary drug. When heated to decomposition it emits acrid smoke and irritating fumes

in vivo

studies showed that administration of quercetin before the initiation stage of carcinogenesis dramatically reduced various chemical agents induced tumor burden in mice models, including benzo(a)pyrene-induced lung tumor burden, azoxymethane-induced preneoplastic lesions in rat colon and n-nitrosodiethylamine-induced hepatocarcinoma etc. [5].

references

quercetin and cancer chemoprevention. evid based complement alternat med. 2011;2011:591356. doi: 10.1093/ecam/neq053. epub 2011 apr 14.food-derived polyphenols inhibit pancreatic cancer growth through mitochondrial cytochrome c release and apoptosis. int j cancer. 2002 apr 10;98(5):761-9.stabilization of p53 is involved in quercetin-induced cell cycle arrest and apoptosis in hepg2 cells. bioscience, biotechnology and biochemistry. 2008;72(3):797–804.survivin and p53 modulate quercetin-induced cell growth inhibition and apoptosis in human lung carcinoma cells. the journal of biological chemistry. 2004the effects of quercetin on antioxidant status and tumor markers in the lung and serum of mice treated with benzo(a)pyrene. biological and pharmaceutical bulletin. 2007

Synthetic route

rutin (153-18-4) → quercetol (117-39-5)

Conditions	Yield
With hydrogenchloride; methanol for 3h; Heating;	96%
With water at 100℃; Kinetics; Ionic liquid;	90%
With sulfuric acid; water at 20℃; for 0.166667h;	89%

hydrogenchloride (7647-01-0) + quercetin triphenylantimony complex (187221-65-4) → quercetol (117-39-5) + triphenylantimony dichloride (594-31-0, 34716-91-1, 20265-29-6)

Conditions	Yield
heating (3 h, water bath); soln. pouring into Petri dish, solid extraction by benzene;	A 75% B 88%

6,8-dibromoquercetin (95412-48-9) → quercetol (117-39-5)

Conditions	Yield
With sodium sulfite In water at 60℃; for 18h; Green chemistry;	87%

2-(3,4-dimethoxyphenyl)-3-hydroxy-5,7-dimethoxy-4H-4-chromenone (1244-78-6) → quercetol (117-39-5)

Conditions	Yield
With boron tribromide In dichloromethane for 6h; Heating;	83%
With trimethylsilyl iodide In methanol at 35℃; for 96h; Inert atmosphere;

Hyperoside (482-36-0) → D-Galactose (10257-28-0) + quercetol (117-39-5)

Conditions	Yield
With sulfuric acid at 100℃; for 1h;	A n/a B 68%
With grape snail enzymes
With rhamnodiastase

antoside → D-Glucose (2280-44-6) + L-rhamnose (73-34-7) + quercetol (117-39-5)

Conditions	Yield
With sulfuric acid at 100℃; for 2h;	A n/a B n/a C 68%
With sulfuric acid at 100℃; for 2h;	A n/a B n/a C 47%

quercetin 7-O-β-D-glucopyranoside (491-50-9, 36450-05-2, 59985-52-3) → quercetol (117-39-5)

Conditions	Yield
Acid hydrolysis;	68%
With sulfuric acid for 1h; Heating;

quercetin 7-O-β-D-glucopyranoside (491-50-9, 36450-05-2, 59985-52-3) → D-glucose (50-99-7) + quercetol (117-39-5)

Conditions	Yield
With water Acidic conditions;	A n/a B 65%
With water Acidic conditions;

isoquercetin (482-35-9) → D-Glucose (2280-44-6) + quercetol (117-39-5)

Conditions	Yield
With sulfuric acid	A n/a B 64.3%
Product distribution; object of study - products of acid hydrolysis;
With 2M HCl In hydrogenchloride at 90℃; for 1h; Product distribution; other reagent;

Hyperoside (482-36-0) → D-Galactose (59-23-4) + quercetol (117-39-5)

Conditions	Yield
With water Acidic conditions;	A n/a B 64%
Acidic conditions;
Acidic aq. solution;

guaijaverin (6743-88-0, 22255-13-6, 72581-59-0, 94131-44-9) → L-(+)-arabinose (87-72-9, 608-45-7, 608-46-8, 608-47-9, 2460-44-8, 6748-95-4, 6763-34-4, 7261-26-9, 7283-06-9, 7283-07-0, 7296-55-1, 7296-56-2, 7296-58-4, 7296-59-5, 7296-60-8, 7296-61-9, 7296-62-0, 7322-30-7, 10257-31-5, 10257-32-6, 10257-33-7, 10257-34-8, 10257-35-9, 19982-83-3, 20242-88-0, 28697-53-2, 36562-42-2, 41546-41-2, 89299-64-9, 107655-34-5, 115794-06-4, 115794-07-5, 130550-15-1, 130606-21-2) + quercetol (117-39-5)

Conditions	Yield
With sulfuric acid for 3h;	A n/a B 63.5%

isoquercetin (482-35-9) → quercetol (117-39-5)

Conditions	Yield
Acidic conditions;	63.3%
With oxonium
With hydrogenchloride; ethanol for 4h; Heating;

Hyperoside (482-36-0) → quercetol (117-39-5)

Conditions	Yield
Acidic conditions;	63.3%
Acid hydrolysis;
With hydrogenchloride In water for 0.5h; Reflux;

rutin (153-18-4) → 6-O-α-L-rhamnopyranosyl-β-D-glucopyranose (552-74-9, 26184-96-3, 47235-47-2, 56906-86-6, 56942-81-5, 68398-81-2, 68567-48-6, 68567-49-7, 75828-90-9, 59246-67-2) + quercetol (117-39-5)

Conditions	Yield
With α-L-rhamnosyl-β-D-glucosidase from Aspergillus niger K2 in Pichia pastoris In aq. phosphate buffer; dimethyl sulfoxide at 35 - 100℃; for 24h; pH=5; Enzymatic reaction;	A 63% B n/a
With rhamnodiastase Reactivity; Enzymatic reaction;
With rutinosidase In water Enzymatic reaction;

coniferol (458-35-5) + rutin (153-18-4) → C22H32O12 + quercetol (117-39-5)

Conditions	Yield
With α-L-rhamnosyl-β-D-glucosidase from Aspergillus niger In dimethyl sulfoxide at 35℃; for 8h; pH=5; Enzymatic reaction;	A 60% B n/a

3,3',4',5,7-pentahydroxy flavanone (215257-15-1) → quercetol (117-39-5)

Conditions	Yield
With potassium pyrosulfite In ethanol at 100℃;	50%
With pyridine; air for 20h; Heating;

rutin (153-18-4) → L-Rhamnose (3615-41-6) + D-glucose (50-99-7) + quercetol (117-39-5)

Conditions	Yield
With sulfuric acid; water	A n/a B n/a C 47%
With sulfuric acid
With hydrogenchloride; water In methanol at 100℃; for 2h;

3,7-dihydroxyflavone (492-00-2) + carbonic acid dimethyl ester (616-38-6) → quercetol (117-39-5)

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene at 90℃; for 72h;	28%

p-hydroxyphenethyl alcohol (501-94-0) + rutin (153-18-4) → rutinose (26184-96-3, 552-74-9, 47235-47-2, 56906-86-6, 56942-81-5, 59246-67-2, 68398-81-2, 68567-48-6, 68567-49-7, 75828-90-9) + quercetol (117-39-5) + 2-(4-hydroxyphenyl)ethyl β-rutinoside

Conditions	Yield
Stage #1: p-hydroxyphenethyl alcohol; rutin In methanol at 40℃; for 30h; Stage #2: With water In methanol for 0.166667h; Reflux; regioselective reaction;	A n/a B n/a C 24%

tamarixetin (603-61-2) → quercetol (117-39-5)

Conditions	Yield
With water; hydrogen iodide; acetic anhydride at 150℃;

3,3'-di-O-methylquercetin (4382-17-6) → quercetol (117-39-5)

Conditions	Yield
With water; hydrogen iodide at 150℃;

2-benzo[1,3]dioxol-5-yl-3-hydroxy-5,7-dimethoxy-chromen-4-one (859439-36-4) → quercetol (117-39-5)

Conditions	Yield
With aluminium trichloride; chlorobenzene at 130℃; Erwaermen des Reaktionsgemisches mit wss. HCl;

rhamnetin (90-19-7) → quercetol (117-39-5)

avicularin (572-30-5) → D-Arabinose (10323-20-3) + quercetol (117-39-5)

Conditions	Yield
With hydrogenchloride for 2h; Heating;

isoquercetin (482-35-9) → β-D-glucose (492-61-5) + quercetol (117-39-5)

Conditions	Yield
Product distribution; acid hydrolysis;

quercitrin (865688-88-6) → D-rhamnose (73-34-7, 87-96-7, 488-79-9, 551-63-3, 609-01-8, 643-17-4, 643-18-5, 4164-09-4, 6014-42-2, 6155-36-8, 6189-71-5, 6696-41-9, 6736-43-2, 13224-93-6, 22611-09-2, 28161-49-1, 28161-50-4, 28161-52-6, 45864-36-6, 63814-64-2, 71116-59-1, 71116-61-5, 72598-05-1, 87936-88-7, 87936-89-8, 97466-79-0, 116908-82-8, 120442-60-6, 123484-22-0, 133576-32-6) + quercetol (117-39-5)

Conditions	Yield
hesperidinase

quercitrin (522-12-3, 22324-77-2, 124827-82-3) → L-rhamnose (73-34-7) + quercetol (117-39-5)

Conditions	Yield
With hydrogenchloride
With sulfuric acid

quercetin-3-arabinoside (6743-88-0, 22255-13-6, 72581-59-0, 94131-44-9) → L-(+)-arabinose (87-72-9, 608-45-7, 608-46-8, 608-47-9, 2460-44-8, 6748-95-4, 6763-34-4, 7261-26-9, 7283-06-9, 7283-07-0, 7296-55-1, 7296-56-2, 7296-58-4, 7296-59-5, 7296-60-8, 7296-61-9, 7296-62-0, 7322-30-7, 10257-31-5, 10257-32-6, 10257-33-7, 10257-34-8, 10257-35-9, 19982-83-3, 20242-88-0, 28697-53-2, 36562-42-2, 41546-41-2, 89299-64-9, 107655-34-5, 115794-06-4, 115794-07-5, 130550-15-1, 130606-21-2) + quercetol (117-39-5)

Conditions	Yield
With hydrogenchloride boiling water bath;

manghaslin (55696-57-6, 124151-38-8) → D-Glucose (2280-44-6) + L-rhamnose (73-34-7, 87-96-7, 488-79-9, 551-63-3, 609-01-8, 643-17-4, 643-18-5, 4164-09-4, 6014-42-2, 6155-36-8, 6189-71-5, 6696-41-9, 6736-43-2, 13224-93-6, 22611-09-2, 28161-49-1, 28161-50-4, 28161-52-6, 45864-36-6, 63814-64-2, 71116-59-1, 71116-61-5, 72598-05-1, 87936-88-7, 87936-89-8, 97466-79-0, 116908-82-8, 120442-60-6, 123484-22-0, 133576-32-6) + quercetol (117-39-5)

Conditions	Yield
With sulfuric acid for 3h; Product distribution; Heating; hydrolysis for structure determination;sugar products were identified as their trimethylsilyl derivatives by GC-MS;

3,3',4',5,7-pentahydroxyflavone 3-O-arabogluocopyranoside (572-30-5, 5041-68-9, 72581-58-9, 119786-64-0, 137332-22-0) → D-arabinofuranose (532-20-7, 613-83-2, 7261-25-8, 7687-39-0, 13221-22-2, 14795-83-6, 15761-67-8, 20074-49-1, 25545-03-3, 25545-04-4, 32445-75-3, 34436-17-4, 36441-93-7, 36468-53-8, 37110-85-3, 37388-49-1, 38029-69-5, 40461-77-6, 40461-89-0, 41546-19-4, 41546-20-7, 41546-21-8, 41546-26-3, 41546-29-6, 41546-30-9, 41546-31-0, 126872-16-0, 131064-98-7) + quercetol (117-39-5)

Conditions	Yield
With hydrogenchloride for 0.25h;

quercetol (117-39-5) + acetic anhydride (108-24-7) → 3,5,7-triacetoxy-2-(3,4-diacetoxy-phenyl)-chromen-4-one (1064-06-8)

Conditions	Yield
With pyridine at 130 - 140℃;	100%
With pyridine at 140 - 145℃; for 4h;	97.5%
With pyridine at 70℃; for 6h;	95%

quercetol (117-39-5) → C30H20O14Se

Conditions	Yield
With hydrogenchloride; selenium(IV) oxide In ethanol; water at 60℃; for 12h; Inert atmosphere;	99.2%

quercetol (117-39-5) + acetic anhydride (108-24-7) → quercetin-3',4',5,7-tetraacetate (7622-90-4)

Conditions	Yield
With magnesium In neat (no solvent) at 25℃; for 3.5h; Temperature;	98%

quercetol (117-39-5) + glucosidase → isoquercetin (482-35-9)

Conditions	Yield
With 1% disodium hydrogen phosphate-sodium citrate; 35-40% glucosyltransferase at 40 - 45℃; Enzymatic reaction;	97.2%

quercetol (117-39-5) + benzoyl chloride (98-88-4) → 2-(3,4-bis(benzoyloxy)phenyl)-4-oxo-4H-chromene-3,5,7-triyl tribenzoate (120036-90-0)

Conditions	Yield
With pyridine In dichloromethane at 20℃; for 3h;	97%
With pyridine at 22 - 24℃; for 4h;	92%
With pyridine at 60℃;	56%
With sodium hydroxide

quercetol (117-39-5) + 2-Methylpropionic anhydride (97-72-3) → 2-(3,4-bis(isobutyryloxy)phenyl)-4-oxo-4H-chromene-3,5,7-triyl tris(2-methylpropanoate) (102607-68-1)

Conditions	Yield
With pyridine for 2h; Reflux;	97%
In pyridine Ambient temperature;	0.43 g

quercetol (117-39-5) + tert-butyldimethylsilyl chloride (18162-48-6) → 3,3',4',5,7-penta-O-tert-butyldimethylsilylquercetin (265975-30-2)

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In dichloromethane at 20℃; for 6h; silylation;	97%
With 1,8-diazabicyclo[5.4.0]undec-7-ene In dichloromethane at 20℃; for 5h;

quercetol (117-39-5) + benzyl bromide (100-39-0) → 2-[3,4-bis(phenylmethoxy)phenyl]-3,5,7-tris(phenylmethoxy)chromen-4-one (13157-90-9)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 72h;	95%
With potassium carbonate In N,N-dimethyl-formamide at 70℃; for 4h; Etherification;	89%
Stage #1: quercetol; benzyl bromide With potassium carbonate In N,N-dimethyl-formamide at 20 - 70℃; for 15h; Stage #2: With water In N,N-dimethyl-formamide at 20℃; for 1h;	80%

quercetol (117-39-5) + benzyl chloride (100-44-7) → 2-[3,4-bis(phenylmethoxy)phenyl]-3,5,7-tris(phenylmethoxy)chromen-4-one (13157-90-9)

Conditions	Yield
With N-benzyl-N,N,N-triethylammonium chloride; potassium carbonate at 20℃; for 35h; Inert atmosphere;	95%
With tetrabutylammomium bromide; potassium carbonate In 1-methyl-pyrrolidin-2-one; acetone at 85 - 90℃; for 24h;	93%
With potassium carbonate; Aethyl-dipropyl-benzyl-ammonium In N,N,N,N,N,N-hexamethylphosphoric triamide for 35h; Inert atmosphere;	90%
With tetrabutylammomium bromide; potassium carbonate In 1-methyl-pyrrolidin-2-one; acetone at 75℃; for 24h; Inert atmosphere;	87%
With potassium carbonate; N,N-dimethyl-formamide at 20℃; for 12h;	15%

quercetol (117-39-5) + sodium acetate (127-09-3) + acetic anhydride (108-24-7) → 3,5,7-triacetoxy-2-(3,4-diacetoxy-phenyl)-chromen-4-one (1064-06-8)

Conditions	Yield
Reflux; Inert atmosphere;	95%

ZnCl2(1,10-phenanthroline) (14049-94-6) + quercetol (117-39-5) → [(1,10-phenanthroline)Zn(Quercetin)Cl].3H2O

Conditions	Yield
With triethylamine In ethanol; water at 20℃; for 0.166667h; Inert atmosphere;	94%

quercetol (117-39-5) → 2-(3',4'-dihydroxybenzoyloxy)-4,6-dihydroxybenzoic acid (30048-34-1)

Conditions	Yield
With oxygen; tetraethylammonium tosylate In N,N-dimethyl-formamide Mechanism; electrolysis at -1.0 V, Au electrode;	93%
With MES buffer; quercetinase EC 1.31.11.24 In dimethyl sulfoxide for 1h; pH=6;
With recombinant quercetinase from Aspergillus japonicus; oxygen In aq. buffer at 40 - 60℃; for 360h; pH=5; Reagent/catalyst; pH-value; Enzymatic reaction;

(2,2'-bipyridyl)dichlorozinc(II) (14491-36-2) + quercetol (117-39-5) → [(2,2'-bipyridine)Zn(Quercetin)Cl].3H2O

Conditions	Yield
With triethylamine In ethanol; water at 20℃; for 0.166667h; Inert atmosphere;	92%

dichloro(1,10-phenanthroline) copper(II) (14783-09-6) + quercetol (117-39-5) → [(1,10-phenanthroline)Cu(Quercetin)Cl].3H2O

Conditions	Yield
With triethylamine In ethanol; water at 20℃; for 0.166667h; Inert atmosphere;	92%

quercetol (117-39-5) + 1-deoxy-1-fluoro-α-D-glucose (2106-10-7) → quercetin 7-α-O-glucoside

Conditions	Yield
With α-glucosidase from sulfolobus solfataricus In dimethyl sulfoxide at 45℃; for 2h; pH=9; Enzymatic reaction;	92%

quercetol (117-39-5) → 2-(3,4-dihydroxy-5-sulfophenyl)-3,5,7-trihydroxy-4H-benzopyran-4-one (31273-65-1)

Conditions	Yield
With sulfuric acid at 80℃; for 2h;	90%

quercetol (117-39-5) → C15H7O16S3(3-)*3K(1+) (116097-14-4) + quercetin-3,7,3',4'-tetrasulphate potassium (90332-36-8, 119560-46-2)

Conditions	Yield
With potassium acetate; tetra(n-butyl)ammonium hydrogensulfate; dicyclohexyl-carbodiimide In pyridine at 25℃; for 288h;	A 89% B n/a

Dichlorodiphenylmethane (2051-90-3) + quercetol (117-39-5) → 2-(2,2-diphenylbenzo[1,3]dioxol-5-yl)-3,5,7-trihydroxychromen-4-one (357194-03-7)

Conditions	Yield
In diphenylether at 175℃; for 2h;	89%
In diphenylether at 175℃; for 2h;	89%
In diphenylether at 175℃; for 0.5h; Inert atmosphere; regioselective reaction;	86%

ethanol (64-17-5) + quercetol (117-39-5) → 2-(3,4-Dihydroxy-phenyl)-2-ethoxy-3,3,5,7-tetrahydroxy-chroman-4-one (102788-22-7)

Conditions	Yield
With oxygen; copper dichloride at 20℃; for 10h;	88%
With phosphate buffer at 80℃; for 7h; Irradiation;	3 mg
With phosphate buffer at 30℃; for 4h; Irradiation; enzyme solution from red clover (leaves and stems);	2 mg

quercetol (117-39-5) + ethyl iodide (75-03-6) → 2-(3,4-diethoxyphenyl)-3,5,7-triethoxy-4H-chromen-4-one (82547-07-7)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 45℃; for 12h; Inert atmosphere;	87%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 15h; Inert atmosphere;	82%
With tetraethylammonium fluoride In N,N-dimethyl-formamide for 20h;	70%
With potassium hydroxide

quercetol (117-39-5) + pivaloyl chloride (3282-30-2) → 2-(3,4-bis(pivaloyloxy)phenyl)-4-oxo-4H-chromene-3,5,7-triyl tris(2,2-dimethylpropanoate)

Conditions	Yield
With pyridine for 2h; Reflux;	87%
With pyridine for 16h; Ambient temperature;	67%

quercetol (117-39-5) → 6-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one

Conditions	Yield
With bromine In 1,4-dioxane at 20 - 22℃; for 2h;	86.1%
Stage #1: quercetol With N-Bromosuccinimide; sodium hydroxide In methanol; water at 20℃; for 0.166667h; Inert atmosphere; Green chemistry; Stage #2: With hydrogenchloride; sodium dithionite In methanol; water at 20℃; Inert atmosphere; Green chemistry;	400 mg
Multi-step reaction with 3 steps 1: potassium carbonate / N,N-dimethyl-formamide / 12 h / 60 °C / Inert atmosphere 2: N-Bromosuccinimide / dichloromethane / -40 °C / Inert atmosphere 3: boron trichloride / dichloromethane; hexane / 2.5 h / -20 °C / Inert atmosphere; Reflux View Scheme
With bromine In 1,4-dioxane at 24.84℃;

quercetol (117-39-5) + methyl iodide (74-88-4) → pentamethyl quercetin (1247-97-8)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 35℃; for 12h; Inert atmosphere;	86%
With sodium hydride In N,N-dimethyl-formamide at 20℃; for 12h;	84%
With potassium carbonate In acetone for 24h; Reflux;	82%

quercetol (117-39-5) → 3,5,7-trihydroxy-2-(3,4-dihydroxyphenyl-2,5,6-D3)-4H-1-benzopyran-4-one-6,8-D2

Conditions	Yield
With boron trifluoride; [D3]phosphoric acid In water-d2 at 55℃; for 48h; deuteration;	86%
Stage #1: quercetol With [D]-sodium hydroxide; platinum on activated charcoal; water-d2 at 130℃; for 9h; Inert atmosphere; Stage #2: With formic acid at 130℃; for 1h; Inert atmosphere;	63%

C35H56O5 (1186389-75-2) + quercetol (117-39-5) → C50H64O11 (1186389-71-8)

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In N,N-dimethyl-formamide at 60℃; Inert atmosphere;	86%

dimethylsulfide (75-18-3) + quercetol (117-39-5) → retusin (1245-15-4)

Conditions	Yield
With potassium hydroxide In water; acetone	86%

quercetol (117-39-5) + L-proline (147-85-3) → quercetin L-proline cocrystals(1:2)

Conditions	Yield
In ethanol at 50℃;	85.5%

Upstream product

• 572-30-5 avicularin 
• 482-35-9 isoquercetin 
• 482-36-0 Hyperoside 
• 865688-88-6 quercitrin 
• 215257-15-1 3,3',4',5,7-pentahydroxy flavanone 
• 153-18-4 rutin 
• 855-97-0 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one 
• 153-18-4 rutin 
• 21637-25-2 isoquercitrin 
• 158560-11-3 quercetin-3-O-β-arabinofuranoside 
• 573690-67-2 8-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one 
• 548-83-4 galangin 
• 125130-61-2 (E)-3-(3,4-methylenedioxyphenyl)-1-(2'-hydroxy-4',5'-dimethoxyphenyl)-2-propen-1-one 
• 90-24-4 2-hydroxy-4,6-dimethoxyacetophenone 

Downstream Products

• 1245-15-4 retusin 
• 78599-47-0 2-(3,4-bis-trimethylsilanyloxy-phenyl)-3-hydroxy-5,7-bis-trimethylsilanyloxy-chromen-4-one 
• 98089-82-8 2-(3,4-dihydroxy-phenyl)-3,5,7-trihydroxy-chromen-4-one; monopotassium-compound 
• 1064-06-8 3,5,7-triacetoxy-2-(3,4-diacetoxy-phenyl)-chromen-4-one 
• 120036-90-0 2-(3,4-bis(benzoyloxy)phenyl)-4-oxo-4H-chromene-3,5,7-triyl tribenzoate 
• 64184-96-9 2-ethoxy-1-(2,4-diethoxy-6-hydroxy-phenyl)-ethanone 
• 82547-03-3 2-(3,4-diethoxyphenyl)-3,7-diethoxy-5-hydroxy-4H-chromen-4-one 
• 82547-07-7 2-(3,4-diethoxyphenyl)-3,5,7-triethoxy-4H-chromen-4-one 
• 1247-97-8 pentamethyl quercetin 
• 108-73-6 3,5-dihydroxyphenol 
• 99-50-3 3,4-Dihydroxybenzoic acid 
• 2068-02-2 2-(3,4-dihydroxyphenyl)-5-hydroxy-3,7-dimethoxychromen-4-one 
• 95412-48-9 6,8-dibromoquercetin 
• 25001-18-7 4,5-dihydroxy-2-(3,5,7-trihydroxy-4-oxo-4H-chromen-2-yl)-benzenesulfonic acid 

Related news

Quercetin (cas 117-39-5) suppressed NADPH oxidase-derived oxidative stress via heme oxygenase-1 induction in macrophages09/04/2019

NADPH oxidase-derived superoxide (O2.-) generation and oxidative stress is usually considered as an important factor to the pathogenesis of inflammatory diseases. Quercetin, widely known for their anti-oxidant and anti-inflammatory properties in vitro and in vivo, is recently identified to induc...detailed

Antioxidant activity of Quercetin (cas 117-39-5) in Eudragit-coated liposomes for intestinal delivery09/03/2019

Quercetin, a natural polyphenol with strong antioxidant activity, was loaded in Eudragit-coated liposomes conceived for intestinal delivery. Eudragit was used to form a protective shell on the surface of liposomes to resist gastric environment and allow the delivery of quercetin to the intestine...detailed

Quercetin (cas 117-39-5) based derivatives as sirtuin inhibitors09/02/2019

Polyphenols synthesized by plants and fungi have various pharmacological effects. The ability of polyphenols to modulate sirtuins has gained considerable interest due to the role of sirtuins in aging, insulin sensitivity, lipid metabolism, inflammation, and cancer. In particular, sirtuin 6 (SIRT...detailed

In silico and in vitro approach of Allium cepa and isolated Quercetin (cas 117-39-5) against MDR bacterial strains and Mycobacterium smegmatis09/01/2019

Pathogenic microorganisms have emerged as Multi Drug Resistant (MDR) and in the past years the infectious diseases caused by MDR have increased dramatically. The aim of this study is to investigate the antibacterial potential of Allium cepa and isolated quercetin along with molecular docking wit...detailed

Quercetin (cas 117-39-5) glycosides prevent dexamethasone-induced muscle atrophy in mice08/31/2019

Although quercetin has numerous biological benefits, including preventing muscle atrophy due to disuse, no reports have been published to date about the preventive effects and molecular mechanisms underlying drug-induced muscle atrophy. Highly soluble and bioavailable quercetin glycosides (QGs) ...detailed

Quercetin (cas 117-39-5) inhibited mesangial cell proliferation of early diabetic nephropathy through the Hippo pathway08/29/2019

Diabetic nephropathy (DN) is one of the most common microvascular complications of diabetes and the leading cause of end-stage renal disease. The proliferation of glomerular mesangial cells (MCs) is a common and prominent pathological change of DN, which takes place at the early stage. Quercetin...detailed

Research ArticleIn vitro bioaccessibility and bioavailability of Quercetin (cas 117-39-5) from the Quercetin (cas 117-39-5)-fortified bread products with reduced glycemic potential08/27/2019

Quercetin, a plant-extracted flavonol, is a potent inhibitor of carbohydrate digestive enzymes. This study aimed to examine: (1) the extent to which quercetin altered the starch digestion and the glycemic potential of the fortified western baked bread as well as oriental steamed bread, (2) the m...detailed

Original articleRedox properties of individual Quercetin (cas 117-39-5) moieties08/26/2019

Quercetin is one of the most prominent and widely studied flavonoids. Its oxidation has been previously investigated only indirectly by comparative analyses of structurally analogous compounds, e.g. dihydroquercetin (taxifolin). To provide direct evidence about the mechanism of quercetin oxidati...detailed

Relevant articles and documents

Studies on the medicinal resources. XXXVI. The constituents of the leaves of Saxifraga stolonifera Meerburg (Saxifragaceae)

-

A triterpene glycoside and flavonoids from leaves of Akebia quinata

-

Chemical constituents of apocynum lancifolium flowers

-

Flavonoids from Gleditsia triacanthos

-

FLAVONOID GLYCOSIDES AND AN ANTHRAQUINONE FROM RUMEX CHALEPENSIS

Besides rutin, quercetin 3-rhamnoside and kaempferol 3-rhamnosyl (1-4)galactoside, and 1,6,8-trihydroxy-1-methyl anthraquinone (emodine) have been characterized from leaves of Rumex chalepensis.The structures were established on the basis of Rf values, acid hydrolysis to aglycone and sugar and UV, EI and FAB-mass-spectra, 1H NMR, 12C DEPT NMR, NOE difference measurements, 1H-H-COSY and 1H-13C COSY spectral data.

Mechanistically elucidating the in vitro safety and efficacy of a novel doxorubicin derivative

Doxorubicin is an effective anticancer drug; however, it is cardiotoxic and has poor oral bioavazilability. Quercetin is a plant-based flavonoid with inhibitory effects on P-glycoprotein (P-gp) and CYP3A4 and also antioxidant properties. To mitigate these therapeutic barriers, DoxQ, a novel derivative of doxorubicin, was synthesized by conjugating quercetin to doxorubicin. The purpose of this study is to mechanistically elucidate the in vitro safety and efficacy of DoxQ. Drug release in vitro and cellular uptake by multidrug-resistant canine kidney (MDCK-MDR) cells were quantified by HPLC. Antioxidant activity, CYP3A4 inhibition, and P-gp inhibitory effects were examined using commercial assay kits. Drug potency was assessed utilizing triple-negative murine breast cancer cells, and cardiotoxicity was assessed utilizing adult rat and human cardiomyocytes (RL-14). Levels of reactive oxygen species and gene expression of cardiotoxicity markers, oxidative stress markers, and CYP1B1 were determined in RL-14. DoxQ was less cytotoxic to both rat and human cardiomyocytes and retained anticancer activity. Levels of ROS and markers of oxidative stress demonstrate lower oxidative damage induced by DoxQ compared to doxorubicin. DoxQ also inhibited the expression and catalytic activity of CYP1B1. Additionally, DoxQ inhibited CYP3A4 and demonstrated higher cellular uptake by MDCK-MDR cells than doxorubicin. DoxQ provides a novel therapeutic approach to mitigate the cardiotoxicity and poor oral bioavailability of doxorubicin. The cardioprotective mechanism of DoxQ likely involves scavenging ROS and CYP1B1 inhibition, while the mechanism of improving the poor oral bioavailability of doxorubicin is likely related to inhibiting CYP3A4 and P-gp.

Exploring the oxidation and iron binding profile of a cyclodextrin encapsulated quercetin complex unveiled a controlled complex dissociation through a chemical stimulus

Background: Flavonoids possess a rich polypharmacological profile and their biological role is linked to their oxidation state protecting DNA from oxidative stress damage. However, their bioavailability is hampered due to their poor aqueous solubility. This can be surpassed through encapsulation to supramolecular carriers as cyclodextrin (CD). A quercetin- 2HP-β-CD complex has been formerly reported by us. However, once the flavonoid is in its 2HP-β-CD encapsulated state its oxidation potential, its decomplexation mechanism, its potential to protect DNA damage from oxidative stress remained elusive. To unveil this, an array of biophysical techniques was used. Methods: The quercetin-2HP-β-CD complex was evaluated through solubility and dissolution experiments, electrochemical and spectroelectrochemical studies (Cyclic Voltammetry), UV–Vis spectroscopy, HPLC-ESI-MS/MS and HPLC-DAD, fluorescence spectroscopy, NMR Spectroscopy, theoretical calculations (density functional theory (DFT)) and biological evaluation of the protection offered against H2O2-induced DNA damage. Results: Encapsulation of quercetin inside the supramolecule's cavity enhanced its solubility and retained its oxidation profile. Although the protective ability of the quercetin-2HP-β-CD complex against H2O2 was diminished, iron serves as a chemical stimulus to dissociate the complex and release quercetin. Conclusions: We found that in a quercetin-2HP-β-CD inclusion complex quercetin retains its oxidation profile similarly to its native state, while iron can operate as a chemical stimulus to release quercetin from its host cavity. General significance: The oxidation profile of a natural product once it is encapsulated in a supramolecular carrier was unveiled as also it was discovered that decomplexation can be triggered by a chemical stimilus.

Elucidation of active site residues of Arabidopsis thaliana flavonol synthase provides a molecular platform for engineering flavonols

Arabidopsis thaliana flavonol synthase (aFLS) catalyzes the production of quercetin, which is known to possess multiple medicinal properties. aFLS is classified as a 2-oxoglutarate dependent dioxygenase as it requires ferrous iron and 2-oxoglutarate for catalysis. In this study, the putative residues for binding ferrous iron (H221, D223 and H277), 2-oxoglutarate (R287 and S289) and dihydroquercetin (H132, F134, K202, F293 and E295) were identified via computational analyses. To verify the proposed roles of the identified residues, 15 aFLS mutants were constructed and their activities were examined via a spectroscopic assay designed in this study. Mutations at H221, D223, H277 and R287 completely abolished enzymes activities, supporting their importance in binding ferrous iron and 2-oxoglutarate. However, mutations at the proposed substrate binding residues affected the enzyme catalysis differently such that the activities of K202 and F293 mutants drastically decreased to approximately 10% of the wild-type whereas the H132F mutant exhibited approximately 20% higher activity than the wild-type. Kinetic analyses established an improved substrate binding affinity in H132F mutant (Km: 0.027 ± 0.0028 mM) compared to wild-type (Km: 0.059 ± 0.0063 mM). These observations support the notion that aFLS can be selectively mutated to improve the catalytic activity of the enzyme for quercetin production.

-

-

One-pot preparation of quercetin using natural deep eutectic solvents

In this study, we have established a green and efficient preparation method of quercetin. Rutin was first extracted from Sophora japonica using natural deep eutectic solvents (NADESs), then hydrolyzed into quercetin by rutin degrading enzyme (RDE) obtained from germinated tartary buckwheat in situ. Rutin solubility tests showed that most of the 11 NADESs increased the solubility of rutin by 67-3116 times compared to water. Thus, NADESs could be prior candidate to extract rutin. Extraction efficiency of rutin varied with different NADESs, and a maximum of 291.57 mg g?1 was achieved in NADES ChGly, which was prepared by mixing choline chloride and glycerol at a molar ratio of 1:1. After that hydrolysis was performed directly in extraction system by adding RDE with degradation rate of up to 8.36 mg min-1·L-1. Our findings suggest that preparation of quercetin using NADESs was simple and feasible to operate, environmentally friendly, efficient, and inspired the preparation method of bioactive components from a new perspective.

Quercetin galactoside gallate in Euphorbiaceae

-

-

-

Flavonoids from Teucrium orientale

-

-

-

Flavonoids from Calendula officinalis flowers

-

-

-

Involvement of rat cytochrome 1A1 in the biotransformation of kaempferol to quercetin: Relevance to the genotoxicity of kaempferol

Kaempferol is a flavonoid widely distributed in edible plants and has been shown to be genotoxic to V79 cells in the absence of external metabolizing systems. The presence of an external metabolizing system, such as rat liver homogenates (S9 mix), leads to an increase in its genotoxicity, which is attributed to its biotransformation to the more genotoxic flavonoid quercetin, via the cytochrome P450 (CYP) mono-oxygenase system. In the present work we investigated the mechanisms of the genotoxicity of kaempferol further. Special attention has been given to the role of CYP in the genotoxicity of this flavonoid. We studied the induction of mutations in Salmonella typhimurium TA98 in the presence and in the absence of S9 mix and the induction of chromosomal aberrations (CAs) and micronuclei (MN) by kaempferol in V79 cells in the presence and in the absence of S9 mix. To evaluate the role of different CYP in the biotransformation of kaempferol we studied the induction of CAs and MN in V79 cells genetically engineered for the expression of rat CYP 1A1, 1A2 and 2B1. In addition we performed CYP inhibition studies using the above-mentioned indicators and high performance liquid chromatography (HPLC) analysis. The results obtained in this work suggest that rat CYP 1A1 is, among the cytochromes studied, the one that plays the major role in the transformation of kaempferol into quercetin. The relevance of these findings to the human situation is discussed.

Hydrolysis of flavonoid glycosides by propolis β-glycosidase

Flavonoids generally occur as O-glycosides with sugars bound in nature, while aglycones and their derivatives are the main flavonoids in propolis. The objective of this work was to study the propolis β-glycosidase activities toward flavonoid β-glycosides and their conjugated forms. β-Glycosidase was extracted from propolis, incubated with avonoid glycosides, and analysed for aglycone formation by HPLC. The results demonstrated that glucose conjugates were rapidly hydrolysed, but not conjugates with other sugars, i.e. rutin and naringin. The rate and extent of deglycosylation depends on the structure of the avonoid and the position of the sugar substituitions. Quercetin 3-O-glucoside had the highest percent of hydrolysis, while quercetin 7-O-glucoside was the least hydrolysed. The Km values for hydrolysis of apigenin 7-glucoside and luteolin-7-O-glucoside were 13M and 20M, respectively.

Transformation of rutin to antiproliferative quercetin-3-glucoside by aspergillus niger

The flavonol quercetin in plants and foods occurs predominantly in the form of glycoside whose sugar moiety affects the bioavailability and the mechanism of its biological activities. The antiproliferative activities of quercetin derivatives such as quercetin aglycone, quercetin-3-ss-D-glucoside (Q3G), and rutin were compared using six different cancer cell lines including colon, breast, hepatocellular, and lung cancer. The IC50 value of Q3G ranged between 15 and 25 μM in HT-29, HCT 116, MCF-7, HepG2, and A549 cells. In these five cell lines, Q3G showed the most potent growth inhibition, whereas rutin showed the least potency. Transformation of rutin to Q3G was conducted by controlling R-L-rhamnosidase and ss-D-glucosidase activities from crude enzyme extract of Aspergillus niger. Carbon sources during culture and transformation conditions such as pH, temperature, and heatstability were optimized. After 4 h biotransformation, 99% of rutin was transformed to Q3G and no quercetin was detected. This study presented an efficient biotransformation for the conversion of rutin to Q3G which was newly shown to have more potent antiproliferative effect than quercetin and rutin. 2010 American Chemical Society.

-

-

-

-

-

-

-

-

Flavonoids from Gossypium hirsutum flowers

-

-

-

Isolation, characterization, complete structural assignment, and anticancer activities of the methoxylated flavonoids from rhamnus disperma roots

Different chromatographic methods including reversed-phase HPLC led to the isolation and purification of three O-methylated flavonoids; 5,4’-dihydroxy-3,6,7-tri-O-methyl flavone (penduletin) (1), 5,3’-dihydroxy-3,6,7,4’,5’-penta-O-methyl flavone (2), and 5-hydroxy-3,6,7,3’,4’,5’-hexa-O-methyl flavone (3) from Rhamnus disperma roots. Additionlly, four flavonoid glycosides; kampferol 7-O-α-L-rhamnopyranoside (4), isorhamnetin-3-O-β-D-glucopyranoside (5), quercetin 7-O-α-L-rhamnopyranoside (6), and kampferol 3, 7-di-O-α-L-rhamnopyranoside (7) along with benzyl-O-β-D-glucopyranoside (8) were successfully isolated. Complete structure characterization of these compounds was assigned based on NMR spectroscopic data, MS analyses, and comparison with the literature. The O-methyl protons and carbons of the three O-methylated flavonoids (1–3) were unambiguously assigned based on 2D NMR data. The occurrence of compounds 1, 4, 5, and 8 in Rhamnus disperma is was reported here for the first time. Compound 3 was acetylated at 5-OH position to give 5-O-acetyl-3,6,7,3’,4’,5’-hexa-O-methyl flavone (9). Compound 1 exhibited the highest cytotoxic activity against MCF 7, A2780, and HT29 cancer cell lines with IC50 values at 2.17 μM, 0.53 μM, and 2.16 μM, respectively, and was 2–9 folds more selective against tested cancer cell lines compared to the normal human fetal lung fibroblasts (MRC5). It also doubled MCF 7 apoptotic populations and caused G1 cell cycle arrest. The acetylated compound 9 exhibited cytotoxic activity against MCF 7 and HT29 cancer cell lines with IC50 values at 2.19 μM and 3.18 μM, respectively, and was 6–8 folds more cytotoxic to tested cancer cell lines compared to the MRC5 cells.