Quercetin

Structural formula
General
Surname	Quercetin
other names	Xanthaurine; Cyanidanol; Cyanidenolone 1522; 3,3 ', 4', 5,7-pentahydroxyflavone; 3 ', 4', 5,7-tetrahydroxyflavon-3-ol; 2- (3,4-Dihydroxyphenyl) -3,5,7-trihydroxy-4 H -1-benzopyran-4-one;
Molecular formula	C 15 H 10 O 7
Brief description	yellow, odorless solid
External identifiers / databases
EC number	204-187-1
ECHA InfoCard	100.003.807
PubChem	5280343
ChemSpider	4444051
DrugBank	DB04216
Wikidata	Q409478
properties
Molar mass	302.24 g mol −1
Physical state	firmly
Melting point	316-317 ° C
solubility	almost insoluble in water; soluble in boiling ethanol , acetic acid and dilute sodium hydroxide solution .;
safety instructions
GHS labeling of hazardous substances danger
H and P phrases	H: 301
	P: 301 + 310 + 330
Toxicological data	161 mg kg −1 ( LD 50 , rat , oral ) ; 159 mg kg −1 ( LD 50 , mouse , oral ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Quercetin (from Latin quercus " oak ") is a yellow natural dye from the group of polyphenols and flavonoids . As a pentahydroxyflavone, it belongs to the subgroup of flavonols. Quercetin is an oxidation product of the anthocyanin dye cyanidin .

Occurrence

Like cyanidin, quercetin occurs naturally as a glycoside or methyl ether. 179 different glycosides are known for quercetin (e.g. rutin or isorhamnetin ).

It is widespread in the plant kingdom and therefore also in food . Large amounts of quercetin can be found in onions , apples , broccoli or green beans , some of which are destroyed depending on how they are prepared. Peeling fruit and vegetables also reduces the flavonoid content drastically, because the flavonoid content is particularly high in the colored peel (flavonoids are plant colorants ). It is also contained in wine . Since quercetin occurs mainly in the grape skin, the levels in red wine are higher than in white wine. In addition, storage in wooden barrels also contributes to the quercetin content, as the substance slowly passes from the wood into the wine during storage.

Lovage ( Levisticum officinale )

The following foods contain high levels of quercetin:

Caper (1800 mg / kg)
Lovage (1700 mg / kg)
Tea ( Camellia sinensis )
Onion - especially in the outermost rings (284–486 mg / kg)
Blueberry (cultivated 74 mg / kg, wild 146–158 mg / kg)
Kale (60-110 mg / kg)
red grape
Apple (21–440 mg / kg)
Chives (245 mg / kg)
Citrus fruits
Broccoli (30 mg / kg) and other leafy green vegetables
green bean (39 mg / kg)
Cherry (32 mg / kg)
raspberry
Black currant (69 mg / kg)
Blackberry (45 mg / kg)
Cranberries (cultivated 83–156 mg / kg, wild 121 mg / kg)
Sweet mountain ash (85 mg / kg)
Sea buckthorn (62 mg / kg)
Crowberry (cultivated 53 mg / kg, wild 56 mg / kg).

A 2007 study found that organically grown tomatoes contained 79% more quercetin than conventionally grown tomatoes .

Physiological importance

The effect of quercetin on mammals is currently (as of 2016) the subject of intensive research. Quercetin is said to have far-reaching, physiologically positive effects. So showed u. a. meanwhile, that 1000 mg / day quercetin for 14 days after high loads led to significantly less sore muscles and a significantly higher performance in the double-blind experiment in athletes than a placebo. The antioxidant potential should be emphasized , as quercetin acts as a radical scavenger, similar to vitamins A, C and E. The exact process of oxidation - inhibition in vivo is, however, still under discussion.

Quercetin also belongs to the group of flavonoids with clearly mutagenic properties, but there is no evidence of toxicity in humans, animal experiments have not shown any carcinogenic effects of flavonoids. Compared to taxifolin , quercetin shows a clear mutagenicity , but this is linked to certain conditions in the cell. Quercetin also works directly against cancer by preventing tumor cells from growing and causing their death.

An in vitro toxicity model has shown that the increased or long-term administration of quercetin can be toxic .

Quercetin blocks the effects of the drug bortezomib in vitro through a direct chemical reaction between quercetin and the boron group.

Studies have shown that it similar to allopurinol , the xanthine oxidase inhibiting and thus hyperuricemia and consequent gout can counteract.

Individual evidence

↑ ^a ^b Quercetin data sheet (PDF) from Carl Roth , accessed on July 20, 2007.

↑ ^a ^b entry on quercetin. In: Römpp Online . Georg Thieme Verlag, accessed on July 25, 2011.

↑ ^a ^b Quercetin data sheet from Sigma-Aldrich , accessed on October 23, 2016 ( PDF ).

↑ ^a ^b Entry on quercetin in the ChemIDplus database of the United States National Library of Medicine (NLM) .

↑ Jens Fleschhut: Investigations on the metabolism, bioavailability and antioxidative effects of anthocyanins , dissertation, 2004 DNB 974478490 urn : nbn: de: swb: 90-26403

↑ P. Schmid: Idacin-degrading enzymes in apples. In: Journal of Food Study and Research. 133, 1967, pp. 304-310, doi: 10.1007 / BF01074568 .

↑ ^a ^b Bernhard Watzl, Gerhard Rechkemmer: Basic knowledge updated: Flavonoide. In: Nutrition review. Volume 48, No. 12, 2001 ( ernaehrungs-umschau.de ).

^ AE Mitchell et al .: Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes. In: Journal of agricultural and food chemistry . 55, No. 15, 2007, pp. 6154-6159, PMID 17590007 .

↑ Ilenia Bazzucchi, Federica Patrizio, Roberta Ceci et al. (2019). The Effects of Quercetin Supplementation on Eccentric Exercise-Induced Muscle Damage. In: Nutrients 11 (1), 205; https://doi.org/10.3390/nu11010205 on . January 30, 2019

↑ SJ Duthie et al .: The effect of dietary flavonoids on DNA damage (strand breaks and oxidized pyrimidines) and growth in human cells. In: Mutation Research . 390, No. 1-2, 1997, pp. 141-151, PMID 9150762 .

↑ Taxifolin ( (2R, 3R) -dihydroquercetin ) is non-mutagenic and only slightly toxic. Taxifolin is redox equivalent (~ constitutional isomer) to cyanidine.

↑ PS Makena et al .: Comparative mutagenic effects of structurally similar flavonoids quercetin and taxifolin on tester strains Salmonella typhimurium TA102 and Escherichia coli WP-2 uvrA. In: Environmental and Molecular Mutagenesis . 50, No. 6, 2009 pp. 451-459, PMID 19326464 .

↑ Anja Klappan: Influence of the flavonoid quercetin on the mTOR signaling pathway of cervical and breast cancer cells . Munich 2014, DNB 1048361322 , urn : nbn: de: bvb: 19-165609 (dissertation, LMU Munich).

↑ B. Ossola et al .: Time-dependent protective and harmful effects of quercetin on 6-OHDA-induced toxicity in neuronal SH-SY5Y cells. In: Toxicology 250, No. 1, 2008, pp. 1-8, PMID 18756631 .

↑ FT Liu et al .: Dietary flavonoids inhibit the anti-cancer effects of the proteasome inhibitor Bortezomib. In: Blood . 112, No. 9, 2008, pp. 3835-3846, PMID 18633129 .

↑ JM Pauff, R. Hille: Inhibition studies of bovine xanthine oxidase by luteolin, silibinin, quercetin, and curcumin. In: Journal of natural products. Volume 72, number 4, April 2009, pp. 725-731, doi: 10.1021 / np8007123 , PMID 19388706 , PMC 2673521 (free full text).

literature

SU Mertens-Talcott, SS Percival: Ellagic acid and quercetin interact synergistically with resveratrol in the induction of apoptosis and cause transient cell cycle arrest in human leukemia cells. In: Cancer Letters . 218, No. 2, 2005, pp. 141-152, doi: 10.1016 / j.canlet.2004.06.007 .
JM Davis et al .: Quercetin reduces susceptibility to influenza infection following stressful exercise. In: American Journal of Physiology-Regulatory, Integrative and Comparative Physiology . 2008; 295: p. R505 – R509, doi: 10.1152 / ajpregu.90319.2008 .

[Roth-1] Quercetin data sheet (PDF) from Carl Roth , accessed on July 20, 2007.

[roempp-2] try on quercetin. In: Römpp Online . Georg Thieme Verlag, accessed on July 25, 2011.

[Sigma-3] Quercetin data sheet from Sigma-Aldrich , accessed on October 23, 2016 ( PDF ).

[ChemIDplus-4] Entry on quercetin in the ChemIDplus database of the United States National Library of Medicine (NLM) .

[5] Jens Fleschhut: Investigations on the metabolism, bioavailability and antioxidative effects of anthocyanins , dissertation, 2004 DNB 974478490 urn : nbn: de: swb: 90-26403

[6] P. Schmid: Idacin-degrading enzymes in apples. In: Journal of Food Study and Research. 133, 1967, pp. 304-310, doi: 10.1007 / BF01074568 .

[Basiswissen-7] Bernhard Watzl, Gerhard Rechkemmer: Basic knowledge updated: Flavonoide. In: Nutrition review. Volume 48, No. 12, 2001 ( ernaehrungs-umschau.de ).

[8] AE Mitchell et al .: Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes. In: Journal of agricultural and food chemistry . 55, No. 15, 2007, pp. 6154-6159, PMID 17590007 .

[9] Ilenia Bazzucchi, Federica Patrizio, Roberta Ceci et al. (2019). The Effects of Quercetin Supplementation on Eccentric Exercise-Induced Muscle Damage. In: Nutrients 11 (1), 205; https://doi.org/10.3390/nu11010205 on . January 30, 2019

[10] SJ Duthie et al .: The effect of dietary flavonoids on DNA damage (strand breaks and oxidized pyrimidines) and growth in human cells. In: Mutation Research . 390, No. 1-2, 1997, pp. 141-151, PMID 9150762 .

[11] Taxifolin ( (2R, 3R) -dihydroquercetin ) is non-mutagenic and only slightly toxic. Taxifolin is redox equivalent (~ constitutional isomer) to cyanidine.

[12] PS Makena et al .: Comparative mutagenic effects of structurally similar flavonoids quercetin and taxifolin on tester strains Salmonella typhimurium TA102 and Escherichia coli WP-2 uvrA. In: Environmental and Molecular Mutagenesis . 50, No. 6, 2009 pp. 451-459, PMID 19326464 .

[13] Anja Klappan: Influence of the flavonoid quercetin on the mTOR signaling pathway of cervical and breast cancer cells . Munich 2014, DNB 1048361322 , urn : nbn: de: bvb: 19-165609 (dissertation, LMU Munich).

[14] B. Ossola et al .: Time-dependent protective and harmful effects of quercetin on 6-OHDA-induced toxicity in neuronal SH-SY5Y cells. In: Toxicology 250, No. 1, 2008, pp. 1-8, PMID 18756631 .

[15] FT Liu et al .: Dietary flavonoids inhibit the anti-cancer effects of the proteasome inhibitor Bortezomib. In: Blood . 112, No. 9, 2008, pp. 3835-3846, PMID 18633129 .

[PMC2673521-16] JM Pauff, R. Hille: Inhibition studies of bovine xanthine oxidase by luteolin, silibinin, quercetin, and curcumin. In: Journal of natural products. Volume 72, number 4, April 2009, pp. 725-731, doi: 10.1021 / np8007123 , PMID 19388706 , PMC 2673521 (free full text).