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Isorhamnetin 3,7,4′-tri-O-β-glucoside
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 (Opuntia ficus-indica (L.)) is also a good source of isorhamnetin, which can be extracted by supercritical fluid extraction assisted by enzymes. Metabolism The enzyme quercetin 3-O-met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-methylated Flavonol
The O-methylated flavonoids or methoxyflavonoids are flavonoids with methylations on hydroxyl groups (methoxy bonds). O-methylation has an effect on the solubility of flavonoids. Enzymes O-methylated flavonoids formation implies the presence of specific O-methyltransferase (OMT) enzymes which accept a variety of substrates. Those enzymes mediate the O-methylation on a specific hydroxyl group, like on 4' (example in ''Catharanthus roseus'') or 3' (example in rice) positions. Those positions can be ortho, meta, para and there can be a special 3-O-methyltransferase for the 3-OH position. Calamondin orange ('' Citrus mitis'') exhibits all of those activities. Plant enzymes * Apigenin 4'-O-methyltransferase * 8-hydroxyquercetin 8-O-methyltransferase * Isoflavone 4'-O-methyltransferase * Isoflavone 7-O-methyltransferase * Isoliquiritigenin 2'-O-methyltransferase * Isoorientin 3'-O-methyltransferase * Kaempferol 4'-O-methyltransferase * Luteolin O-methyltransferase * Methylquerc ... [...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 native to Iraq, Lebanon, Syria, and Turkey. 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 of quercetin Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, s .... References External links Rhamnazin on the Extrasynthese catalogue O-methylated flavonols Diols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamarixetin
Tamarixetin is an O-methylated flavonol, a naturally occurring flavonoid. It has been isolated from '' Tamarix ramosissima''. See also * Isorhamnetin, the 3'-methyl analog * List of antioxidants in food * List of phytochemicals in food The following is a list of phytochemicals present in foods. Terpenoids (isoprenoids) Carotenoids ( tetraterpenoids) ''Carotenes'' orange pigments * α-Carotene – to vitamin A: carrots, pumpkins, maize, tangerine, orange * β-Carote ... References Flavonols Tetrols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Phytochemicals In Food
The following is a list of phytochemicals present in foods. Terpenoids (isoprenoids) Carotenoids ( tetraterpenoids) ''Carotenes'' orange pigments * α-Carotene – to vitamin A: carrots, pumpkins, maize, tangerine, orange * β-Carotene – to vitamin A: dark, leafy greens, red, orange and yellow fruits and vegetables. * γ-Carotene - to vitamin A * δ-Carotene * ε-carotene * Lycopene: Vietnamese Gac, tomatoes, grapefruit, watermelon, guava, apricots, carrots, autumn olive. * Neurosporene: tomato, pink grapefruit,watermelon * Phytofluene: star fruit, sweet potato, orange * Phytoene: sweet potato, orange '' Xanthophylls'' yellow pigments * Canthaxanthin: paprika, mushrooms, crustaceans, fish and eggs . * β-Cryptoxanthin to vitamin A: mango, tangerine, orange, papaya, peaches, avocado, pea, grapefruit, kiwi * Zeaxanthin: wolfberry, spinach, kale, turnip greens, maize, eggs, red pepper, pumpkin, orange * Astaxanthin: microalgae, yeast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Antioxidants In Food
This is a list of antioxidants naturally occurring in food. Vitamin C and vitamin E – which are ubiquitous among raw plant foods – are confirmed as dietary antioxidants, whereas vitamin A becomes an antioxidant following metabolism of provitamin A beta-carotene and cryptoxanthin. Most food compounds listed as antioxidants – such as polyphenols common in colorful, edible plants – have antioxidant activity only in vitro, as their fate in vivo is to be rapidly metabolized and excreted, and the in vivo properties of their metabolites remain poorly understood. For antioxidants added to food to preserve them, see butylated hydroxyanisole and butylated hydroxytoluene. Regulatory guidance In the following discussion, the term "antioxidant" refers mainly to non-nutrient compounds in foods, such as polyphenols, which have ''antioxidant capacity'' in vitro and so provide an artificial index of antioxidant strength – the oxygen radical absorbance capacity (ORAC) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-methylquercetin 7-O-methyltransferase
In enzymology, a 3-methylquercetin 7-O-methyltransferase () is an enzyme that catalyzes the chemical reaction :S-adenosyl-L-methionine + 5,7,3',4'-tetrahydroxy-3-methoxyflavone \rightleftharpoons S-adenosyl-L-homocysteine + 5,3',4'-trihydroxy-3,7-dimethoxyflavone Thus, the two substrates of this enzyme are S-adenosyl methionine and 5,7,3',4'-tetrahydroxy-3-methoxyflavone (isorhamnetin), whereas its two products are S-adenosylhomocysteine and 5,3',4'-trihydroxy-3,7-dimethoxyflavone (rhamnazin). This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:5,7,3',4'-tetrahydroxy-3-methoxyflavone 7-O-methyltransferase. Other names in common use include flavonol 7-O-methyltransferase, flavonol 7-methyltransferase, 7-OMT, S-adenosyl-L-methionine:3',4',5,7-tetrahydroxy-3-methoxyflavone, 7-O-methyltransferase, and 3-methylquercitin 7-O-methyltransferase is- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavonol
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, and an unrelated group of metabolically important molecules, the flavins (with "i"), derived from the yellow B vitamin riboflavin. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
