Def. "any of many compounds that are plant metabolites, being formally derived from flavone; they have antioxidant properties,[1] and sometimes contribute to flavor[2]" is called a flavonoid.

The raw dandelion flowers contain diverse phytochemicals, including polyphenols, such as flavonoids apigenin, isoquercitrin (a quercetin-like compound), and caffeic acid, as well as terpenoids, triterpenes, and sesquiterpenes.[3] The roots contain a substantial amount of the prebiotic fiber inulin. Dandelion greens contain lutein.[4]

Flavonoids (or bioflavonoids; from the Latin word flavus, meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in diets.[5]

The tartness of cranberry juice derives from its mixed content of polyphenols, including flavonoids, proanthocyanidins, anthocyanins, phenolic acids, and ellagitannins.[6]

Chemically, flavonoids have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and a heterocyclic ring (C, the ring containing the embedded oxygen).[5][7] This carbon structure can be abbreviated C6-C3-C6. According to the IUPAC nomenclature,[8][9] they can be classified into:

  • flavonoids or bioflavonoids
  • isoflavonoids, derived from 3-phenylchromen-4-one (3-phenyl-1,4-benzopyrone) structure
  • neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyrone) structure

Flavonoids (vitexin, casticin), iridoid glycoside (agnuside, aucubin), p-hydroxybenzoic acid,[10][11] alkaloids, essential oils, fatty oils, diterpenoids and steroids have been identified in the chemical analysis of Vitex agnus-castus.[12] They occur in the fruits and in the leaves.[11]

Anthocyanidins edit

Anthoxanthins edit

Flavones edit

Flavonols edit

Herbacetin is a flavonol, a type of flavonoid.

Quercetin edit

Quercetin is a plant flavonol from the flavonoid group of polyphenols found in many fruits, vegetables, leaves, seeds, and grains; red onions and kale are common foods containing appreciable amounts of quercetin.[13]

Quercetin is a flavonoid widely distributed in nature.[13] The name has been used since 1857, and is derived from quercetum (oak forest), after the oak genus Quercus.[14][15] It is a naturally occurring polar auxin transport inhibitor.[16]

Quercetin is one of the most abundant dietary flavonoids,[13][17] with an average daily consumption of 25–50 milligrams.[18]

Foods Quercetin
capers, raw 234[17]
capers, canned 173[17]
lovage leaves, raw 170[17]
buckwheat seeds 90
rumex (dock) like sorrel 86[17]
radish leaves 70[17]
carob fiber 58[17]
dill 55[19]
cilantro 53[17]
Hungarian wax pepper 51[17]
fennel leaves 49[17]
red onion 32[17]
radicchio 32[17]
watercress 30[17]
kale 23[17]
chokeberry 19[17]
Vaccinium uliginosum (bog blueberry) 18[17]
cranberry 15[17]
lingonberry 13[17]
black plums 12[17]

In red onions, higher concentrations of quercetin occur in the outermost rings and in the part closest to the root, the latter being the part of the plant with the highest concentration.[20] One study found that organically grown tomatoes had 79% more quercetin than non-organically grown fruit.[21] Quercetin is present in various kinds of honey from different plant sources.[22]

"Quercetin is a flavonoid that helps to control allergy symptoms of rhinitis and sinusitis. It stabilizes the membranes of mast cells, reducing the release of histamine. It is also helpful in lowering the risk of cataract by inhibiting glycoprotein formation in the lens (Cornish, et al 2002). Typical doses of quercetin are 800 mg to 1200 mg daily."[23]

Rutins edit

Rutin (rutoside or rutinoside)[13] and other dietary flavonols are under preliminary clinical research for their potential biological effects, such as in reducing post-thrombotic syndrome, venous insufficiency, or endothelial dysfunction, but there was no high-quality evidence for their safe and effective uses as of 2018.[13][24][25] As a flavonol among similar flavonoids, rutin has low bioavailability due to poor absorption, high metabolism, and rapid excretion that collectively make its potential for use as a therapeutic agent limited.[13]

Flavanones edit

Hesperidin[26] occurs in Valerian.

6-methylapigenin[26] occurs in Valerian.

Linarin[27] occurs in Valerian.





Flavanonols edit

Flavans edit

Flavanols edit

Def. any "of a class of flavonoids that use the 2-phenyl-3,4-dihydro-2H-chromen-3-ol molecular skeleton"[28] is called a flavanol.

Herbacetin is a flavonol, a type of flavonoid.

Proanthocyanidins edit

Proanthocyanidins, including the lesser bioactive and bioavailable polymers (four or more catechins) represent a group of condensed flavan-3-ols, such as procyanidins, prodelphinidins and propelargonidins, that can be found in many plants, most notably apples, maritime pine bark and that of most other pine species, cinnamon,[29] aronia fruit, cocoa beans, grape seed, grape skin (procyanidins and prodelphinidins).[30] Cocoa beans contain the highest concentrations.[31]

Proanthocyanidins also may be isolated from Quercus petraea and Quercus robur heartwood (wine barrel oaks).[32] Açaí oil, obtained from the fruit of the açaí palm (Euterpe oleracea), is rich in numerous procyanidin oligomers.[33]

Apples contain on average per serving about eight times the amount of proanthocyanidin found in wine, with some of the highest amounts found in the Red Delicious and Granny Smith varieties.[34]

An extract of maritime pine bark called Pycnogenol bears 65-75 percent proanthocyanidins (procyanidins).[35]

Proanthocyanidin glycosides can be isolated from cocoa liquor.[36]

The seed testas of field beans (Vicia faba) contain proanthocyanidins[37] that affect the digestibility in piglets[38] and could have an inhibitory activity on enzymes.[39] Cistus salviifolius also contains oligomeric proanthocyanidins.[40]

Isoflavonoids edit

Isoflavones edit

Isoflavanes edit

Isoflavandiols edit

Isoflavenes edit

Coumestans edit

Pterocarpans edit

Neoflavonoids edit

See also edit

References edit

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  2. -sche (2 August 2020). "flavonoid". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 8 August 2021. {{cite web}}: |author= has generic name (help)
  3. Katrin Schütz, Reinhold Carle; Andreas Schieber (2006). "Taraxacum—a review on its phytochemical and pharmacological profile". Journal of Ethnopharmacology 107 (3): 313–323. doi:10.1016/j.jep.2006.07.021. PMID 16950583. 
  4. "Carotenoids". Micronutrient Information Center, Linus Pauling Institute, Oregon State University. 1 July 2016. Retrieved 27 June 2019.
  5. 5.0 5.1 Delage, PhD, Barbara (November 2015). "Flavonoids". Linus Pauling Institute, Oregon State University, Corvallis, Oregon. Retrieved 2021-01-26.
  6. Blumberg, JB; Camesano, TA; Cassidy, A; Kris-Etherton, P; Howell, A; Manach, C; Ostertag, LM; Sies, H et al. (2013). "Cranberries and their bioactive constituents in human health.". Advances in Nutrition 4 (6): 618–32. doi:10.3945/an.113.004473. ISSN 2161-8313. PMID 24228191. PMC 3823508. // 
  7. "Analysis of Conformational, Structural, Magnetic, and Electronic Properties Related to Antioxidant Activity: Revisiting Flavan, Anthocyanidin, Flavanone, Flavonol, Isoflavone, Flavone, and Flavan-3-ol". ACS Omega 6 (13): 8908–8918. April 2021. doi:10.1021/acsomega.0c06156. PMID 33842761. 
  8. IUPAC Compendium of Chemical Terminology (2nd ed.). Oxford: Blackwell Scientific. 1997. doi:10.1351/goldbook.F02424. ISBN 978-0-9678550-9-7. 
  9. "Flavonoids (isoflavonoids and neoflavonoids)". The Gold Book. 2009. doi:10.1351/goldbook. ISBN 978-0-9678550-9-7. Retrieved 16 September 2012. 
  10. "Chaste tree". 9 October 2017. Retrieved 20 August 2019.
  11. 11.0 11.1 Hoberg, Eva; Meier, Beat; Sticher, Otto (2000). "An analytical high performance liquid chromatographic method for the determination of agnuside and p-hydroxybenzoic acid contents in Agni-casti fructus". Phytochemical Analysis 11 (5): 327–329. doi:10.1002/1099-1565(200009/10)11:5<327::AID-PCA523>3.0.CO;2-0. 
  12. Hajdú, Zsuzsanna; Hohmann, Judit; Forgo, Peter; Martinek, Tamás; Dervarics, Máté; Zupkó, István; Falkay, György; Cossuta, Daniel et al. (2007). "Diterpenoids and flavonoids from the fruits of Vitex agnus-castus and antioxidant activity of the fruit extracts and their constituents". Phytotherapy Research 21 (4): 391–394. doi:10.1002/ptr.2021. PMID 17262892. 
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  14. "Quercetin". Merriam-Webster.
  15. "Quercetin (biochemistry)". Encyclopædia Britannica.
  16. "Induction of Zygotic Polyembryos in Wheat: Influence of Auxin Polar Transport". The Plant Cell 9 (10): 1767–1780. Oct 1997. doi:10.1105/tpc.9.10.1767. PMID 12237347. PMC 157020. // 
  17. 17.00 17.01 17.02 17.03 17.04 17.05 17.06 17.07 17.08 17.09 17.10 17.11 17.12 17.13 17.14 17.15 17.16 17.17 17.18 "USDA Database for the Flavonoid Content of Selected Foods, Release 3" (PDF). U.S. Department of Agriculture. 2011.
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  19. Justesen U, Knuthsen P (May 2001). "Composition of flavonoids in fresh herbs and calculation of flavonoid intake by use of herbs in traditional Danish dishes". Food Chemistry 73 (2): 245–50. doi:10.1016/S0308-8146(01)00114-5. 
  20. "Onions: a source of unique dietary flavonoids". Journal of Agricultural and Food Chemistry 55 (25): 10067–80. December 2007. doi:10.1021/jf0712503. PMID 17997520. 
  21. "Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes". Journal of Agricultural and Food Chemistry 55 (15): 6154–9. Jul 2007. doi:10.1021/jf070344+. PMID 17590007. 
  22. "Analysis of flavonoids in honey by HPLC coupled with coulometric electrode array detection and electrospray ionization mass spectrometry". Analytical and Bioanalytical Chemistry 400 (8): 2555–63. Jun 2011. doi:10.1007/s00216-010-4614-7. PMID 21229237. 
  23. Michael Janson (September 2006). "Orthomolecular medicine: the therapeutic use of dietary supplements for anti-aging". Clinical Interventions in Aging 1 (3): 261-5. PMID 18046879. Retrieved 25 September 2018. 
  24. Morling, J. R; Yeoh, S. E; Kolbach, D. N (November 2018). "Rutosides for treatment of post-thrombotic syndrome". Cochrane Database of Systematic Reviews 11 (11): CD005625. doi:10.1002/14651858.CD005625.pub4. PMID 30406640. 
  25. Martinez-Zapata, M. J; Vernooij, R. W; Uriona Tuma, S. M; Stein, A. T; Moreno, R. M; Vargas, E; Capellà, D; Bonfill Cosp, X (January 2021). "Phlebotonics for venous insufficiency". Cochrane Database of Systematic Reviews 4: CD003229. doi:10.1002/14651858.CD003229.pub3. PMID 27048768. 
  26. 26.0 26.1 Marder M, Viola H, Wasowski C, Fernández S, Medina JH, Paladini AC (2003). "6-methylapigenin and hesperidin: new valeriana flavonoids with activity on the CNS". Pharmacol Biochem Behav 75 (3): 537–45. doi:10.1016/S0091-3057(03)00121-7. PMID 12895671. 
  27. Fernández S, Wasowski C, Paladini AC, Marder M (2004). "Sedative and sleep-enhancing properties of linarin, a flavonoid-isolated from Valeriana officinalis". Pharmacol Biochem Behav 77 (2): 399–404. doi:10.1016/j.pbb.2003.12.003. PMID 14751470. 
  28. Visviva (5 March 2009). "flavanol". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 8 August 2021. {{cite web}}: |author= has generic name (help)
  29. María Luisa Mateos-Martín, Elisabet Fuguet, Carmen Quero, Jara Pérez-Jiménez, Josep Lluís Torres; Fuguet; Quero; Pérez-Jiménez; Torres (2012). "New identification of proanthocyanidins in cinnamon (Cinnamomum zeylanicum L.) using MALDI-TOF/TOF mass spectrometry". Analytical and Bioanalytical Chemistry 402 (3): 1327–1336. doi:10.1007/s00216-011-5557-3. PMID 22101466. 
  30. Souquet, J; Cheynier, Véronique; Brossaud, Franck; Moutounet, Michel (1996). "Polymeric proanthocyanidins from grape skins". Phytochemistry 43 (2): 509–512. doi:10.1016/0031-9422(96)00301-9. 
  31. "USDA Database for the Proanthocyanidin Content of Selected Foods – 2004" (PDF). USDA. 2004. Retrieved 24 April 2014.
  32. Vivas, N; Nonier, M; Pianet, I; Vivasdegaulejac, N; Fouquet, E (2006). "Proanthocyanidins from Quercus petraea and Q. robur heartwood: quantification and structures". Comptes Rendus Chimie 9: 120–126. doi:10.1016/j.crci.2005.09.001. 
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  34. Hammerstone, John F.; Lazarus, Sheryl A.; Schmitz, Harold H. (August 2000). "Procyanidin content and variation in some commonly consumed foods". The Journal of Nutrition 130 (8S Suppl): 2086S–92S. doi:10.1093/jn/130.8.2086S. PMID 10917927. "Figure 5" 
  35. Rohdewald, P (2002). "A review of the French maritime pine bark extract (Pycnogenol), a herbal medication with a diverse clinical pharmacology". International Journal of Clinical Pharmacology and Therapeutics 40 (4): 158–68. doi:10.5414/cpp40158. PMID 11996210. 
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  37. Merghem, R.; Jay, M.; Brun, N.; Voirin, B. (2004). "Qualitative analysis and HPLC isolation and identification of procyanidins fromvicia faba". Phytochemical Analysis 15 (2): 95–99. doi:10.1002/pca.731. PMID 15116939. 
  38. Van Der Poel, A. F. B.; Dellaert, L. M. W.; Van Norel, A.; Helsper, J. P. F. G. (2007). "The digestibility in piglets of faba bean (Vicia faba L.) as affected by breeding towards the absence of condensed tannins". British Journal of Nutrition 68 (3): 793–800. doi:10.1079/BJN19920134. PMID 1493141. 
  39. Griffiths, D. W. (1981). "The polyphenolic content and enzyme inhibitory activity of testas from bean (Vicia faba) and pea (Pisum spp.) varieties". Journal of the Science of Food and Agriculture 32 (8): 797–804. doi:10.1002/jsfa.2740320808. 
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Further reading edit

External links edit