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Catechins
Flavan-3-ols (sometimes referred to as flavanols) are a subgroup of flavonoids. They are derivatives of flavans that possess a 2-phenyl-3,4-dihydro-2''H''-chromen-3-ol skeleton. Flavan-3-ols are structurally diverse and include a range of compounds, such as catechin, epicatechin gallate, epigallocatechin, epigallocatechin gallate, proanthocyanidins, theaflavins, thearubigins. They are found in most plants and have a role in plant defense. Chemical structure The single-molecule (monomer) catechin, or isomer epicatechin (see diagram), adds four hydroxyls to flavan-3-ol, making building blocks for concatenated polymers (proanthocyanidins) and higher order polymers (anthocyanidins). Flavan-3-ols possess two chiral carbons, meaning four diastereoisomers occur for each of them. They are distinguished from the yellow, ketone-containing flavonoids such as quercitin and rutin, which are called flavonols. Early use of the term bioflavonoid was imprecisely applied to include the flava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catechin
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic juice or boiled extract of ''Mimosa catechu'' (''Acacia catechu'' L.f). Chemistry Catechin possesses two benzene ring Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atom ...s (called the A- and B-rings) and a dihydropyran heterocycle (the C-ring) with a hydroxyl group on carbon 3. The A-ring is similar to a resorcinol moiety while the B-ring is similar to a catechol moiety. There are two chirality (chemistry), chiral centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in trans configura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catechin Molecule File
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic juice or boiled extract of ''Mimosa catechu'' (''Acacia catechu'' L.f). Chemistry Catechin possesses two benzene rings (called the A- and B-rings) and a dihydropyran heterocycle (the C-ring) with a hydroxyl group on carbon 3. The A-ring is similar to a resorcinol moiety while the B-ring is similar to a catechol moiety. There are two chiral centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in trans configuration and are called ''catechin'' and the other two are in cis configuration and are called ''epicatechin''. The most common catechin isomer is (+)-catechin. The other stereoisomer is (-)-catechin or ''ent''-catechin. The most common epicatechin isomer is (-)-epicatechin (al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catechin
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic juice or boiled extract of ''Mimosa catechu'' (''Acacia catechu'' L.f). Chemistry Catechin possesses two benzene ring Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atom ...s (called the A- and B-rings) and a dihydropyran heterocycle (the C-ring) with a hydroxyl group on carbon 3. The A-ring is similar to a resorcinol moiety while the B-ring is similar to a catechol moiety. There are two chirality (chemistry), chiral centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in trans configura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicatechin
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic juice or boiled extract of ''Mimosa catechu'' (''Acacia catechu'' L.f). Chemistry Catechin possesses two benzene rings (called the A- and B-rings) and a dihydropyran heterocycle (the C-ring) with a hydroxyl group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy g ... on carbon 3. The A-ring is similar to a resorcinol moiety while the B-ring is similar to a catechol moiety. There are two chirality (chemistry), chiral centers on the molecule on carbons 2 and 3. Therefore, it has four diastereoisomers. Two of the isomers are in trans configura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigallocatechin Gallate
Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin. EGCG – the most abundant catechin in tea – is a polyphenol under basic research for its potential to affect human health and disease. EGCG is used in many dietary supplements. Food sources Tea It is found in high content in the dried leaves of green tea (7380 mg per 100 g), white tea (4245 mg per 100 g), and in smaller quantities, black tea (936 mg per 100 g). During black tea production, the catechins are mostly converted to theaflavins and thearubigins via polyphenol oxidases. Other Trace amounts are found in apple skin, plums, onions, hazelnuts, pecans, and carob powder (at 109 mg per 100 g). Bioavailability When taken orally, EGCG has poor absorption even at daily intake equivalent to 8–16 cups of green tea, an amount causing adverse effects such as nausea or heartburn. After consumption, EGCG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proanthocyanidin
Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex polyphenols, having the same polymeric building block, form the group of tannins. Proanthocyanidins were discovered in 1947 by Jacques Masquelier, who developed and patented techniques for the extraction of oligomeric proanthocyanidins from pine bark and grape seeds. Often associated with prevention of urinary tract infections (UTIs) by consuming cranberries, grape seeds or red wine, proanthocyanidins have not been conclusively shown as effective for preventing or treating UTIs. Distribution in plants 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. They can be found in many plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proanthocyanidin
Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex polyphenols, having the same polymeric building block, form the group of tannins. Proanthocyanidins were discovered in 1947 by Jacques Masquelier, who developed and patented techniques for the extraction of oligomeric proanthocyanidins from pine bark and grape seeds. Often associated with prevention of urinary tract infections (UTIs) by consuming cranberries, grape seeds or red wine, proanthocyanidins have not been conclusively shown as effective for preventing or treating UTIs. Distribution in plants 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. They can be found in many plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thearubigin
Thearubigins are polymeric polyphenols that are formed during the enzymatic oxidation and condensation of two gallocatechins (epigallocatechin and epigallocatechin gallate) with the participation of polyphenol oxidases during the fermentation reactions in black tea. Thearubigins are red in colour and are responsible for much of the staining effect of tea. Therefore, a black (fully oxidized) tea often appears red while a green or white tea has a much clearer appearance. The colour of a black tea, however, is affected by many other factors as well, such as the amount of theaflavins, another oxidized form of polyphenols. Thearubigins were first studied by Roberts, E. A. H. in the 1960s by the means of spectroscopy or by fractionation or paper chromatography. They have been identified as proanthocyanidins in 1969. The thearubigins formation has been studied in an in vitro model in 1983. Thearubigins from black tea extracts have been studied by degradation in 1996. Quantification metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavan-3-ol
Flavan-3-ols (sometimes referred to as flavanols) are a subgroup of flavonoids. They are derivatives of flavans that possess a 2-phenyl-3,4-dihydro-2''H''-chromen-3-ol skeleton. Flavan-3-ols are structurally diverse and include a range of compounds, such as catechin, epicatechin gallate, epigallocatechin, epigallocatechin gallate, proanthocyanidins, theaflavins, thearubigins. They are found in most plants and have a role in plant defense. Chemical structure The single-molecule (monomer) catechin, or isomer epicatechin (see diagram), adds four hydroxyls to flavan-3-ol, making building blocks for concatenated polymers (proanthocyanidins) and higher order polymers (anthocyanidins). Flavan-3-ols possess two chiral carbons, meaning four diastereoisomers occur for each of them. They are distinguished from the yellow, ketone-containing flavonoids such as quercitin and rutin, which are called flavonols. Early use of the term bioflavonoid was imprecisely applied to include the flava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicatechin Gallate
Epicatechin gallate (ECG) is a flavan-3-ol, a type of flavonoid, present in green tea. It is also reported in buckwheat and in grape. The tea component epicatechin gallate is being researched because in vitro experiments showed it can reverse methicillin resistance in bacteria such as ''Staphylococcus aureus''. Nevertheless, the compound is significantly degraded by steeping in boiling water, unlike related catechins. Epicatechin, as well as many other flavonoids, has been found to act as a non-selective antagonist of the opioid receptors, albeit with somewhat low affinity. References See also * List of phytochemicals in food * Green tea extract Green tea is a type of tea that is made from ''Camellia sinensis'' leaves and buds that have not undergone the same withering and oxidation process which is used to make oolong teas and black teas. Green tea originated in China, and since then ... Flavanols CB1 receptor agonists Kappa-opioid receptor antagonists Mu- ... [...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 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-phenyl chromen-4-one (3-phenyl-1,4-benzopyrone) structure *neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-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 bioflavonoid have also been more loosely used to describe non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theaflavin
Theaflavin (TF) and its derivatives, known collectively as ''theaflavins'', are antioxidant polyphenols that are formed from the condensation of flavan-3-ols in tea leaves during the enzymatic oxidation (sometimes erroneously referred to as fermentation) of black tea. Theaflavin-3-gallate, theaflavin-3'-gallate, and theaflavin-3-3'-digallate are the main theaflavins. Theaflavins are types of thearubigins, and are therefore reddish in color. Those molecules contain a tropolone moiety. Certain benefits of black tea containing TFs can include the ability to whiten skin in cosmetics and support antiobesity by affecting lipid metabolism. The radical scavenging function remains under investigation. See also * Theaflavin 3-gallate Theaflavin-3-gallate is a theaflavin derivative. It can be found in abundance in black tea and is produced during fermentation. It has been studied as a cancer-fighting chemical when combined with cisplatin against ovarian cancer cells. Consuming ... Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
