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Isorhamnetin 3-rutinoside
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. 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-methyltransferase uses S-adenosyl methionine and quercetin to produce S-adenosylhomocysteine and isorhamnetin. The enzyme 3-methylquercetin 7-O-methyltransferase uses S-adenosyl methionine and 5,7,3',4'-tetra ... [...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 * Methylquercet ... [...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 of quercetin. It can be found in ''Croton schiedeanus''. It can also be synthetized. Biosynthesis The enzyme 3,7-dimethylquercetin 4 .... References External links Rhamnazin on the Extrasynthese catalogue O-methylated flavonols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamarixetin
Tamarixetin is an O-methylated flav-on-ol, a naturally occurring flavonoid. See also * Isorhamnetin, the 3'-methyl analog * List of antioxidants in food * List of phytochemicals in food While there is ample evidence to indicate the health benefits of diets rich in fruits, vegetables, legumes, whole grains and nuts, no specific food has been acknowledged by scientists and government regulatory authorities as providing a health bene ... External links Tamarixetin on chemblink.com Flavonols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Phytochemicals In Food
While there is ample evidence to indicate the health benefits of diets rich in fruits, vegetables, legumes, whole grains and nuts, no specific food has been acknowledged by scientists and government regulatory authorities as providing a health benefit. Current medical research is focused on whether health effects could be due to specific essential nutrients or to phytochemicals which are not defined as essential. The following is a list of phytochemicals present in commonly consumed foods. Terpenoids (isoprenoids) Carotenoids ( tetraterpenoids) ''Carotenes'' orange pigments * α-Carotene – to vitamin A . * β-Carotene – to vitamin A . * γ-Carotene - to vitamin A, * δ-Carotene * ε-carotene * Lycopene . * Neurosporene * Phytofluene . * Phytoene . ''Xanthophylls'' yellow pigments * Canthaxanthin . * β-Cryptoxanthin to vitamin A . * Zeaxanthin . * Astaxanthin . * Lutein . * Rubixanthin . Triterpenoid * Saponins . * Oleanolic acid . * Ursolic acid . * Be ... [...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 ORAC measurement. Other than for dietary antio ... [...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 A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ... of this enzyme class is S-adenosyl-L-methionine:5,7,3',4'-tetrahydroxy-3-methoxyflavone 7-O-methy ... [...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. 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] |
