Remedy/Flavonoids

Def. "any of many compounds that are plant metabolites, being formally derived from flavone; they have antioxidant properties, and sometimes contribute to flavor" 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. The roots contain a substantial amount of the prebiotic fiber inulin. Dandelion greens contain lutein.

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.

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

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). This carbon structure can be abbreviated C6-C3-C6. According to the IUPAC nomenclature, 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, alkaloids, essential oils, fatty oils, diterpenoids and steroids have been identified in the chemical analysis of Vitex agnus-castus. They occur in the fruits and in the leaves.

Flavonols

Herbacetin is a flavonol, a type of flavonoid.

Quercetin

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.

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

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

Foods	Quercetin (mg/100g)
capers, raw	234
capers, canned	173
lovage leaves, raw	170
buckwheat seeds	90
rumex (dock) like sorrel	86
radish leaves	70
carob fiber	58
dill	55
cilantro	53
Hungarian wax pepper	51
fennel leaves	49
red onion	32
radicchio	32
watercress	30
kale	23
chokeberry	19
Vaccinium uliginosum (bog blueberry)	18
cranberry	15
lingonberry	13
black plums	12

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. One study found that organically grown tomatoes had 79% more quercetin than non-organically grown fruit. Quercetin is present in various kinds of honey from different plant sources.

"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."

Rutins

Rutin (rutoside or rutinoside) 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. 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.

Flavanones

Hesperidin occurs in Valerian.

6-methylapigenin occurs in Valerian.

Linarin occurs in Valerian.

Hesperetin

Naringenin

Eriodictyol

Homoeriodictyol

Flavanols

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

Herbacetin is a flavonol, a type of flavonoid.

Proanthocyanidins

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, aronia fruit, cocoa beans, grape seed, grape skin (procyanidins and prodelphinidins). Cocoa beans contain the highest concentrations.

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

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.

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

Proanthocyanidin glycosides can be isolated from cocoa liquor.

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

See also

• Alcohols
• Glandular system
• Hair colors
• Human skin pigmentation
• Minerals
• Nutraceuticals
• Oils
• Pigmented lesions of the oromucosa
• Plants
• Polyphenols
• Terpenoids
• Vitamins
• Waxes

Further reading

• Eric Braverman (1979). "Orthomolecular Medicine and Megavitamin Therapy: Future and Philosophy". Orthomolecular Psychiatry 8 (4): 265-72. http://www.orthomolecular.org/library/jom/1979/pdf/1979-v08n04-p265.pdf. Retrieved 2014-08-20.