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Theasinensin D
Theasinensin D is polyphenol flavonoid found in oolong tea. It's an atropisomer of theasinensin A Theasinensin A is polyphenol flavonoid from black tea ('' Camellia sinensis'') created during fermentation, by oxidation of epigallocatechin gallate. Its atropisomer is theasinensin D. See also *Theasinensin B Theasinensin B is polyphenol .... References * * Flavanols Polyphenols Biphenyls {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oolong Tea
Oolong (, ; (''wūlóngchá'', "dark dragon" tea)) is a traditional semi-oxidized Chinese tea ('' Camellia sinensis)'' produced through a process including withering the plant under strong sun and oxidation before curling and twisting.Zhongguo Chajing pp. 222–234, 271–282, 419–412, chief editor: Chen Zhongmao, publisher: Shanghai Wenhua Chubanshe (Shanghai Cultural Publishers) 1991. Most oolong teas, especially those of fine quality, involve unique tea plant cultivars that are exclusively used for particular varieties. The degree of oxidation, which varies according to the chosen duration of time before firing, can range from 8 to 85%, depending on the variety and production style. Oolong is especially popular in south China and among ethnic Chinese in Southeast Asia as is the Fujian preparation process known as the Gongfu tea ceremony. Different styles of oolong tea can vary widely in flavor. They can be sweet and fruity with honey aromas, or woody and thick with roast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atropisomer
Atropisomers are stereoisomers arising because of hindered rotation about a single bond, where energy differences due to steric strain or other contributors create a barrier to rotation that is high enough to allow for isolation of individual conformers. They occur naturally and are important in pharmaceutical design. When the substituents are achiral, these conformers are enantiomers (''atropoenantiomers''), showing axial chirality; otherwise they are diastereomers (''atropodiastereomers''). Etymology and history The word ''atropisomer'' ( el, άτροπος, , meaning "without turn") was coined in application to a theoretical concept by German biochemist Richard Kuhn for Karl Freudenberg's seminal ''Stereochemie'' volume in 1933. Atropisomerism was first experimentally detected in a tetra substituted biphenyl, a diacid, by George Christie and James Kenner in 1922. Michinori Ōki further refined the definition of atropisomers taking into account the temperature-dependence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theasinensin A
Theasinensin A is polyphenol flavonoid from black tea (''Camellia sinensis'') created during fermentation, by oxidation of epigallocatechin gallate. Its atropisomer is theasinensin D. See also * Theasinensin B *Theasinensin C *Theasinensin D *Theasinensin E *Theasinensin F *Theasinensin G Theasinensin G is polyphenol flavonoid found in oolong tea. It is a deoxy derivative of theasinensin D and atropisomer of theasinensin F Theasinensin F is polyphenol flavonoid found in oolong tea. It's a deoxy derivative of theasinensin A ... References * * * Flavanols Polyphenols Biphenyls {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavanols
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenols
Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments. Etymology The name derives from the Ancient Greek word (''polus'', meaning "many, much") and the word phenol which refers to a chemical structure formed by attaching to an aromatic benzenoid (phenyl) ring to a hydroxyl (-OH) group as is found in alcohols (hence the ''-ol'' suffix). The term polyphenol has been in use at least since 1894. Definition The term polyphenol is not well-defined, but is generally agreed that they are natural products "having a polyphenol structure (i.e., several hydroxyl groups on aromatic rings)" including four principal classes: "phenolic acids, flavonoids, stilbenes, and lignans". *Flavonoids include flavones, flavonols, flavanols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
