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Flavonols
Flavonols are a class of flavonoids that have the 3-hydroxyflavone backbone (IUPAC name : 3-hydroxy-2-phenylchromen-4-one). Their diversity stems from the different positions of the phenolic -OH groups. They are distinct from flavanols (with "a") such as catechin, another class of flavonoids. Flavonols are present in a wide variety of fruits and vegetables. In Western populations, estimated daily intake is in the range of 20–50 mg per day for flavonols. Individual intake varies depending on the type of diet consumed. The phenomenon of dual fluorescence (due to excited state intramolecular proton transfer or ESIPT) is induced by tautomerism of flavonols (and glucosides) and could contribute to plant UV protection and flower colour. Besides being a subclass of flavonoids, flavonols are suggested by a study of cranberry juice to play a role along with proanthocyanidins, in the juice's ability to block bacterial adhesion, demonstrated by the compressing the fimbria of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavonoid
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 the diets of humans. Chemically, flavonoids have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and a Heterocyclic compound, 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-phenylchromone, chromen-4-one (3-phenyl-1,4-benzopyran, benzopyrone) structure *neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyran, benzopyrone) structure The three flavonoid classes above are all ketone-containing compounds and as such, anthoxanthins (flavones and flavonols). This class was the first to be termed bioflavonoids. The terms flavonoid and bioflav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myricetin
Myricetin is a member of the flavonoid class of polyphenolic compounds, with antioxidant properties. Common dietary sources include vegetables (including tomatoes), fruits (including oranges), nuts, berries, tea, and red wine. Myricetin is structurally similar to fisetin, luteolin, and quercetin and is reported to have many of the same functions as these other members of the flavonol class of flavonoids. Reported average intake of myricetin per day varies depending on diet, but has been shown in the Netherlands to average 23 mg/day. Myricetin is produced from the parent compound taxifolin through the (+)-dihydromyricetin intermediate and can be further processed to form laricitrin and then syringetin, both members of the flavonol class of flavonoids. Dihydromyricetin is frequently sold as a supplement and has controversial function as a partial GABAA receptor potentiator and treatment in Alcohol Use Disorder (AUD). Myricetin can alternatively be produced directly from kae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaempferol
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 . 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.Kaempferol at .com; retrieved October 20, 2017 Natural occurrence Kaempferol is a secondary metabolite found in many plants, plant-derived foods, and traditional medicines. Its flavor is considered bitter. In plants and food< ...
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Gossypetin
Gossypetin, also known as 3,5,7,8,3',4'-hexahydroxyflavone, is a flavonol, a type of flavonoid. It has been isolated from the flowers and the calyx of '' Hibiscus sabdariffa'' (roselle) and exhibits a strong antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ... activity. The compound has also been found to act as an antagonist of TrkB. Recently it was shown that gossypetin has radioprotective activity. The enzyme 8-hydroxyquercetin 8-''O''-methyltransferase uses ''S''-adenosyl methionine and gossypetin to produce ''S''-adenosylhomocysteine and 3,5,7,3',4'-pentahydroxy-8-methoxyflavone. In 2022, a study in an animal model using intragastric administration suggested that the flavonoid gossypetin facilitated the clearance of beta-amyloid in the brain and is a promis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quercetin
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. Occurrence 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. 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 pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morin (flavonoid)
Morin is a yellow chemical compound that can be isolated from ''Maclura pomifera'' (Osage orange), ''Maclura tinctoria'' (old fustic), and from leaves of ''Psidium guajava'' (common guava). In a preclinical ''in vitro'' study, morin was found to be a weak inhibitor of fatty acid synthase with an IC50 of 2.33 μM. Morin was also found to inhibit amyloid formation by islet amyloid polypeptide (or amylin) and disaggregate amyloid fibers. Morin exhibit inhibitory action against IgE-mediated allergic response. Morin treatment significantly down-regulated expressions of BLT2, NF-κB, and Th2-cytokine (TNF-α, IL-1β, IL-4, IL-6, and IL-13) in lungs of murine model of allergic asthma. Morin can be used to test for the presence of aluminium or tin in a solution, since it forms characteristically fluorescent coordination complexes with them. Glycosides * Morin-3-O- arabinoside * Morin-3-O-lyxoside Lyxose is an aldopentose — a monosaccharide containing five carbon atoms, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galangin
Galangin is a flavonol, a type of flavonoid. Occurrence Galangin is found in high concentrations in plants like ''Alpinia officinarum'' (lesser galangal) and ''Helichrysum aureonitens''. It is also found in the rhizome of ''Alpinia galanga'' and in propolis. Biological activities Galangin has been shown to have ''in vitro'' antibacterial and antiviral activity. It also inhibits the growth of breast tumor cells ''in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...''. References External links Galangin on Chemblink.com {{flavonol Flavonols Resorcinols Steroid sulfotransferase inhibitors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fisetin
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. The biological activity of fisetin has been studied in many laboratory assays; like other polyphenols it has many activities. Biological sources Fisetin can be found in a wide variety of plants. It is found in Eudicotyledons, such as trees and shrubs in the family Fabaceae, such as the acacias ''Acacia greggii'' and '' Acacia berlandieri'', the parrot tree (''Butea frondosa''), the honey locust (''Gleditsia triacanthos''), members of the family Anacardiaceae such as the '' Quebracho colorado'' and species of the genus ''Rhus'', which contains the sumacs. Along with myricetin, fisetin provides the color of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamnetin
Rhamnetin is an O-methylated flavonol, a type of chemical compound. It can be isolated from cloves. The structure of the molecule was discovered by Austrian chemist Josef Herzig Josef Herzig (25 September 1853 – 4 July 1924) was an Austrian chemist. Herzig was born in Sanok, Galicia, which at that time was part of Austria-Hungary. Herzig went to school in Breslau until 1874, started studying chemistry at the U ... (1853–1924). Glycosides Rhamnetin is the aglycone of xanthorhamnin. O-methylated flavonols Catechols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamnazin
Rhamnazin is an ''O''-methylated flavonol, a type of chemical compound. It can be found in '' Rhamnus petiolaris'', a buckthorn plant endemic to Sri Lanka. Metabolism The enzyme 3-methylquercetin 7-''O''-methyltransferase uses ''S''-adenosyl methionine and isorhamnetin to produce ''S''-adenosyl homocysteine and rhamnazin. The enzyme 3,7-dimethylquercetin 4'-''O''-methyltransferase uses ''S''-adenosyl methionine and rhamnazin to produce ''S''-adenosyl homocysteine and ayanin Ayanin is an ''O''-methylated flavonol, a type of flavonoid. It is the 3,7,4'-tri-''O''-methylated derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output .... References External links Rhamnazin on the Extrasynthese catalogue O-methylated flavonols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
