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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. Consumin ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenols In Tea
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouthfeel of tea. Polyphenols in tea include catechins, theaflavins, tannins, and flavonoids. Polyphenols found in green tea include, but are not limited to, epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin; flavanols such as kaempferol, quercetin, and myricitin are also found in green tea. Catechins Catechins include epigallocatechin-3-gallate (EGCG), epicatechin (EC), epicatechin-3-gallate (ECg), epigallocatechin (EGC), catechin, and gallocatechin (GC).The content of EGCG is higher in green tea. Catechins constitute about 25% of the dry mass of a fresh tea leaf, although total catechin content varies widely depending on species, clonal variation, growing location, season, light variation, and altitude. They are present in nearly all teas made from '' Camellia sinens ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thearubigins
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 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theaflavin Digallate
Theaflavin digallate (TFDG) is an antioxidant natural phenol found in black tea, and a theaflavin derivative. Health * TFDG is a scavenger of superoxide ''in vitro'', even more so than EGCG. * Tea polyphenols including TFDG reduce angiogenesis, which is implicated in non-liquid cancers, an area of intense current research, by decreasing vascular endothelial growth factor Vascular endothelial growth factor (VEGF, ), originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, ... production and receptor phosphorylation. * TFDG inhibits activity of the enzyme 3CLpro ''in vitro''. References {{Thearubigin Thearubigins Phenol antioxidants SARS-CoV-2 main protease inhibitors ... [...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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 large amounts of black tea has been reported to reduce the effects of aging in female populations.Y. Oka, S. Iwai, H. Amano et al., “Tea polyphenols inhibit rat osteoclast formation and differentiation,” ''Journal of Pharmacological Sciences'' 118 (1): 55–64, 2012. See also * 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 ... References Thearubigins Tropolones Pyrogallols Benzoate esters Enediols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropolone
Tropolone is an organic compound with the chemical formula . It is a pale yellow solid that is soluble in organic solvents. The compound has been of interest to research chemists because of its unusual electronic structure and its role as a ligand precursor. Although not usually prepared from tropone, it can be viewed as its derivative with a hydroxyl group in the 2-position. Synthesis and reactions Many methods have been described for the synthesis of tropolone. One involves bromination of 1,2-cycloheptanedione with ''N''-bromosuccinimide followed by dehydrohalogenation at elevated temperatures, while another uses acyloin condensation of the ethyl ester of pimelic acid the acyloin again followed by oxidation by bromine. : An alternate route is a +2cycloaddition of cyclopentadiene with a ketene to give a bicyclo .2.0eptyl structure, followed by hydrolysis and breakage of the fusion bond to give the single ring: : Thy hydroxyl group of tropolone is acidic, having a p''K'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 large amounts of black tea has been reported to reduce the effects of aging in female populations.Y. Oka, S. Iwai, H. Amano et al., “Tea polyphenols inhibit rat osteoclast formation and differentiation,” ''Journal of Pharmacological Sciences'' 118 (1): 55–64, 2012. See also * 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 ... References Thearubigins Tropolones Pyrogallols Benzoate esters Enediols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants, to prevent oxidation, and to foods to prevent spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress. The only dietary antioxidants are vitamins A, C, and E, but the term ''antioxidant'' has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro, with little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans. History As part of their adaptation from marine life, terrestrial plants began producing non-marine a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermentation (tea)
Tea processing is the method in which the leaves from the tea plant ''Camellia sinensis'' are transformed into the dried leaves for brewing tea. The categories of tea are distinguished by the processing they undergo. In its most general form, tea processing involves different manners and degrees of oxidation of the leaves, stopping the oxidation, forming the tea and drying it. The innate flavor of the dried tea leaves is determined by the type of cultivar of the tea bush, the quality of the plucked tea leaves, and the manner and quality of the production processing they undergo. After processing, a tea may be blended with other teas or mixed with flavourants to alter the flavor of the final tea. When producing black, pu'erh and oolong teas there is an additional purpose of processing: to encourage oxidization, which further develops flavour and aroma compounds. History The history of tea processing corresponds intimately with the role that tea played in Chinese society and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Tea
Black tea, also translated to red tea in various East Asian languages, is a type of tea that is more oxidized than oolong, yellow, white and green teas. Black tea is generally stronger in flavour than other teas. All five types are made from leaves of the shrub (or small tree) ''Camellia sinensis,'' though '' Camellia taliensis'' is also used rarely. Two principal varieties of the species are used – the small-leaved Chinese variety plant (''C. sinensis'' var. ''sinensis''), used for most other types of teas, and the large-leaved Assamese plant (''C. sinensis'' var. ''assamica''), which was traditionally mainly used for black tea, although in recent years some green and white teas have been produced. First originating in China, the beverage's name there is ''hong cha'' (, "red tea") due to the color of the oxidized leaves when processed appropriately. Today, the drink is widespread throughout East and Southeast Asia, both in consumption and harvesting, including in China, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenol Antioxidants
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs. Properties Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water at phenol to wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
