Flavonoids are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Polyphenols are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.
Nelumbo nucifera, also known as sacred lotus, Indian lotus, or simply lotus, is one of two extant species of aquatic plant in the family Nelumbonaceae. It is sometimes colloquially called a water lily, though this more often refers to members of the family Nymphaeaceae.
Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor and is used as an ingredient in dietary supplements, beverages, and foods.
Naringenin is a flavanone from the flavonoid group of polyphenols and is commonly found in a variety of citrus fruits and is the predominant flavonone in grapefruit. Naringenin has demonstrated numerous biological activities, including anti-inflammatory properties, antioxidant activity and skin healing. It is used as a cosmetic ingredient and dietary supplement. Naringenin is thought to be responsible for CYP3A4 suppression in the intestinal wall, that may result in serious changes of pharmacokinetics in drugs related with this enzyme.
Rutin is the glycoside combining the flavonol quercetin and the disaccharide rutinose. It is a flavonoid glycoside found in a wide variety of plants, including citrus.
Kaempferol (3,4′,5,7-tetrahydroxyflavone) is a natural flavonol, a type of flavonoid, found in a variety of plants and plant-derived foods including kale, beans, tea, spinach, and broccoli. Kaempferol is a yellow crystalline solid with a melting point of 276–278 °C (529–532 °F). It is slightly soluble in water and highly soluble in hot ethanol, ethers, and DMSO. Kaempferol is named for 17th-century German naturalist Engelbert Kaempfer.
A polyphenol antioxidant is a hypothetized type of antioxidant, in which each instance would contain a polyphenolic substructure; such instances which have been studied in vitro. Numbering over 4,000 distinct chemical structures, such polyphenols may have antioxidant activity {{{1}}} in vitro (although they are unlikely to be antioxidants in vivo). Hypothetically, they may affect cell-to-cell signaling, receptor sensitivity, inflammatory enzyme activity or gene regulation, although high-quality clinical research has not confirmed any of these possible effects in humans as of 2020.
Flavonols are a class of flavonoids that have the 3-hydroxyflavone backbone. Their diversity stems from the different positions of the phenolic –OH groups. They are distinct from flavanols such as catechin, another class of flavonoids, and an unrelated group of metabolically important molecules, the flavins, derived from the yellow B vitamin riboflavin.
The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers (catechins) and flavanol polymers (proanthocyanidins). This large group of natural phenols can be broadly separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color and mouthfeel of the wine. The non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids.
Fisetin (7,3′,4′-flavon-3-ol) is a plant flavonol from the flavonoid group of polyphenols. It can be found in many plants, where it serves as a yellow/ochre colouring agent. It is also found in many fruits and vegetables, such as strawberries, apples, persimmons, onions and cucumbers. Its chemical formula was first described by Austrian chemist Josef Herzig in 1891.
Isorhamnetin is an O-methylated flavon-ol from the class of flavonoids. A common food source of this 3'-methoxylated derivative of quercetin and its glucoside conjugates are pungent yellow or red onions, in which it is a minor pigment, quercetin-3,4'-diglucoside and quercetin-4'-glucoside and the aglycone quercetin being the major pigments. Pears, olive oil, wine and tomato sauce are rich in isorhamnetin. Almond skin is a rich source of isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside, in some cultivars they comprise 75% of the polyphenol content, the total of which can exceed 10 mg/100 gram almond. Others sources include the spice, herbal medicinal and psychoactive Mexican tarragon (Tagetes lucida), which is described as accumulating isorhamnetin and its 7-O-glucoside derivate. Nopal is also a good source of isorhamnetin, which can be extracted by supercritical fluid extraction assisted by enzymes.
Taxifolin (5,7,3',4'-flavan-on-ol), also known as dihydroquercetin, belongs to the subclass flavanonols in the flavonoids, which in turn is a class of polyphenols. It is extracted from plants such as Siberian larch and milk thistle.
Syringetin is an O-methylated flavonol, a type of flavonoid. It is found in red grape, in Lysimachia congestiflora and in Vaccinium uliginosum. It is one of the phenolic compounds present in wine.
In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. Phenolic compounds are produced by plants and microorganisms. Organisms sometimes synthesize phenolic compounds in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. As they are present in food consumed in human diets and in plants used in traditional medicine of several cultures, their role in human health and disease is a subject of research. Some phenols are germicidal and are used in formulating disinfectants.
Hypericum hirsutum is a species of flowering plant in the family Hypericaceae, commonly known as hairy St John's-wort. It is found in Western Europe.
Quercetin 3-sulfate is a plasma human metabolite of quercetin. It is the sulfate conjugate of quercetin.
trans-Resveratrol-3-O-glucuronide is a metabolite of resveratrol and trans-resveratrol-3-O-glucoside (piceid).
Sanguiin H-6 is an ellagitannin.
Tetradium ruticarpum is a tree that comes from China and Korea. It was previously classified in the genus Euodia as Euodia ruticarpa. The fruit is usually used, denoted sometimes as fructus. It has a strong bitter taste, and is used in traditional Chinese medicine (TCM) and is a recognized herb in Kampo. Both the former genus name and the species name are often misspelled, and the plant usually appears in sources dealing with traditional Chinese medicine as "Evodia(e) rutaecarpa".
