General Description
Yellow needles or yellow powder. Converts to anhydrous form at 203-207°F. Alcoholic solutions taste very bitter.
Reactivity Profile
QUERCETIN(117-39-5) is a strong antioxidant and a metal chelator. Promotes the formation of nitrosamines .
Air & Water Reactions
Sensitive to exposure to air and light. Insoluble in water.
Hazard
Questionable carcinogen.
Health Hazard
ACUTE/CHRONIC HAZARDS: When heated to decomposition this compound emits acrid smoke and irritating fumes.
Fire Hazard
Flash point data for this compound are not available; however, QUERCETIN is probably combustible.
Description
The name of quercetin(117-39-5) 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.
Definition
ChEBI: Quercetin is a pentahydroxyflavone having the five hydroxy groups placed at the 3-, 3'-, 4'-, 5- and 7-positions. It is one of the most abundant flavonoids in edible vegetables, fruit and wine. It has a role as an antibacterial agent, an antioxidant, a protein kinase inhibitor, an antineoplastic agent, an EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor, a plant metabolite, a phytoestrogen, a radical scavenger, a chelator, an Aurora kinase inhibitor and a geroprotector. It is a pentahydroxyflavone and a 7-hydroxyflavonol. It is a conjugate acid of a quercetin-7-olate.
Indications
It is mainly used for the treatment of chronic bronchitis.
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(117-39-5) 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.
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
