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Valoneic Acid
Valoneic acid is a hydrolysable tannin. It is a component of some hydrolysable tannins such as mallojaponin. The difference with its isomer sanguisorbic acid is that the hydroxyl that links the hexahydroxydiphenoyl (HHDP) group to the galloyl group belongs to the HHDP group. It can be chemically synthesized.Enantioselective synthesis of valoneic acid derivative. Hitoshi Abe, Yusuke Sahara, Yuki Matsuzaki, Yasuo Takeuchi and Takashi Harayama, Tetrahedron Letters, Volume 49, Issue 4, 21 January 2008, pp. 605-609, See also * Sanguisorbic acid * Valonea (''Quercus macrolepis'') * Valoneic acid dilactone Valoneic acid dilactone is a hydrolysable tannin that can be isolated from the heartwood of '' Shorea laevifolia''5A-Reductase inhibitory tannin-related compounds isolated from Shorea laevifolia. Yoshio Hirano, Ryuichiro Kondo and Kokki Sakai, Jou ... References External links Plant polyphenols: vegetable tannins revisited, page 136by Edwin Haslam Ellagitannins Biph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysable Tannin
A hydrolysable tannin or pyrogallol-type tannin is a type of tannin that, on heating with hydrochloric or sulfuric acids, yields gallic or ellagic acids. At the center of a hydrolysable tannin molecule, there is a carbohydrate (usually D-glucose but also cyclitols like quinic or shikimic acids). The hydroxyl groups of the carbohydrate are partially or totally esterified with phenolic groups such as gallic acid in gallotannins or ellagic acid in ellagitannins. Hydrolysable tannins are mixtures of polygalloyl glucoses and/or poly-galloyl quinic acid derivatives containing in between 3 up to 12 gallic acid residues per molecule. Hydrolysable tannins are hydrolysed by weak acids or weak bases to produce carbohydrate and phenolic acids. Examples of gallotannins are the gallic acid esters of glucose in tannic acid (C76H52O46), found in the leaves and bark of many plant species. Hydrolysable tannins can be extracted from different vegetable plants, such as chestnut wood (''Cast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mallojaponin
Mallojaponin is a hydrolysable tannin found in the bark of ''Mallotus japonicus''. This compound contains the moiety elaeocarpusinic acid, an oxidized hexahydroxydiphenic acid group (dehydrohexahydroxydiphenic acid or DHHDP) which reacted with a dehydroascorbic acid molecule. It also contains a valoneic acid and a gallic acid Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plant ... moieties linked to a glucose molecule. References Ellagitannins {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanguisorbic Acid
Sanguisorbic acid is a constituent of some ellagitannins. It is constituted by a hexahydroxydiphenic acid unit linked by an O-C bond to a gallic acid. The differences with its isomers, valoneic acid and nonahydroxytriphenic acid, are that the hydroxyl that links the hexahydroxydiphenoyl (HHDP) group to the galloyl group belongs to the galloyl group in valoneic acid, while in nonahydroxytriphenic acid, the hexahydroxydiphenic acid unit is linked by a C-C bond to gallic acid Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plant .... It is found in 2,3-O-hexahydroxydiphenoyl-4,6-O-sanguisorboyl-(α/β)-glucose, an ellagitannin found in '' Rubus sanctus''. It is also found in lambertianin A, B, C and D, all ellagitannins found in '' Rubus lambertianus''. See also * Valoneic acid R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexahydroxydiphenic Acid
Hexahydroxydiphenic acid is an organic compound with the formula HO)3C6HCO2Hsub>2. It is the oxidatively coupled derivative of gallic acid It is a white solid, although samples are typically brown owing to oxidation. Occurrence left, 142px, Ellagic acid. Luteic acid and ellagic acid are the mono- and di lactone of hexahydroxydiphenic acid, respectively. Hexahydroxydiphenic acid is a component of some ellagitannin image:Castalagin.svg, 130px, Castalagin is a representative ellagitannin, characterized by coupled gallic acid substituents The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol formed primarily from the oxidative link ...s, such as casuarictin. See also * Diphenic acid References Ellagitannins Pyrogallols Biphenyls Trihydroxybenzoic acids {{phenol-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallic Acid
Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. It is a white solid, although samples are typically brown owing to partial oxidation. Salts and esters of gallic acid are termed "gallates". Its name is derived from oak galls, which were historically used to prepare tannic acid. Despite the name, gallic acid does not contain gallium. Isolation and derivatives Gallic acid is easily freed from gallotannins by acidic or alkaline hydrolysis. When heated with concentrated sulfuric acid, gallic acid converts to rufigallol. Hydrolyzable tannins break down on hydrolysis to give gallic acid and glucose or ellagic acid and glucose, known as gallotannins and ellagitannins, respectively. Biosynthesis Gallic acid is formed from 3-dehydroshikimate by the action of the enzyme shikimat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valoneic Vs Sanguisorbic
Valoneic acid is a hydrolysable tannin. It is a component of some hydrolysable tannins such as mallojaponin. The difference with its isomer sanguisorbic acid is that the hydroxyl that links the hexahydroxydiphenoyl (HHDP) group to the galloyl group belongs to the HHDP group. It can be chemically synthesized.Enantioselective synthesis of valoneic acid derivative. Hitoshi Abe, Yusuke Sahara, Yuki Matsuzaki, Yasuo Takeuchi and Takashi Harayama, Tetrahedron Letters, Volume 49, Issue 4, 21 January 2008, pp. 605-609, See also * Sanguisorbic acid * Valonea (''Quercus macrolepis'') * Valoneic acid dilactone Valoneic acid dilactone is a hydrolysable tannin that can be isolated from the heartwood of '' Shorea laevifolia''5A-Reductase inhibitory tannin-related compounds isolated from Shorea laevifolia. Yoshio Hirano, Ryuichiro Kondo and Kokki Sakai, Jou ... References External links Plant polyphenols: vegetable tannins revisited, page 136by Edwin Haslam Ellagitannins Biph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanguisorbic Acid
Sanguisorbic acid is a constituent of some ellagitannins. It is constituted by a hexahydroxydiphenic acid unit linked by an O-C bond to a gallic acid. The differences with its isomers, valoneic acid and nonahydroxytriphenic acid, are that the hydroxyl that links the hexahydroxydiphenoyl (HHDP) group to the galloyl group belongs to the galloyl group in valoneic acid, while in nonahydroxytriphenic acid, the hexahydroxydiphenic acid unit is linked by a C-C bond to gallic acid Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plant .... It is found in 2,3-O-hexahydroxydiphenoyl-4,6-O-sanguisorboyl-(α/β)-glucose, an ellagitannin found in '' Rubus sanctus''. It is also found in lambertianin A, B, C and D, all ellagitannins found in '' Rubus lambertianus''. See also * Valoneic acid R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valonea
''Quercus ithaburensis'' subsp. ''macrolepis'', the Valonia oak, is a subspecies of ''Quercus ithaburensis'', a member of the beech family, Fagaceae. It may also be treated as a separate species, ''Quercus macrolepis''. Taxonomy The Valonia oak was first described as the species ''Quercus macrolepis'' by Carl Friedrich Kotschy in 1860. It was reduced to a subspecies of ''Quercus ithaburensis'' in 1981. Within the oak genus, ''Q. ithaburensis'' is classified in the subgenus ''Cerris'', section ''Cerris'', which includes ''Quercus cerris'', the Turkey oak, and related species. It is most closely related to ''Quercus brantii'', Brant's oak. Distribution ''Quercus ithaburensis'' subsp. ''macrolepis'' is native from south-east Italy, through the Balkans (Albania, Bulgaria, former Yugoslavia) and Greece, including Crete and the East Aegean Islands), to the eastern Mediterranean (Turkey, Lebanon and Syria. It is absent from the Palestine region The region of Palestin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valoneic Acid Dilactone
Valoneic acid dilactone is a hydrolysable tannin that can be isolated from the heartwood of '' Shorea laevifolia''5A-Reductase inhibitory tannin-related compounds isolated from Shorea laevifolia. Yoshio Hirano, Ryuichiro Kondo and Kokki Sakai, Journal of wood science, Volume 49, Number 4, pp.339-343, and in oaks species like the North American white oak (''Quercus alba'') and European red oak (''Quercus robur ''Quercus robur'', the pedunculate oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native plant, native to most of Europe and western Asia, and is widely cultivated in other temperate regions. It ...'').Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry. Pirjo Mämmelä, Heikki Savolainenb, Lasse Lindroosa, Juhani Kangasd and Terttu Vartiainen, Journal of Chromatography A, Volume 891, Issue 1, 1 September 2000, Pages 75-83, It shows an inhibitory effect on 5α-reductase, an enzyme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edwin Haslam
Edwin Haslam (1932 – 3 October 2013) was an organic chemist and an author of books on s. He was an alumnus of Sir John Deane's College in Northwich, Cheshire, United Kingdom and was for many years Professor of Organic Chemistry at the University of Sheffield
The University of Sheffield (informally Sheffield University or TUOS) is a public univ ...
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Ellagitannins
image:Castalagin.svg, 130px, Castalagin is a representative ellagitannin, characterized by coupled gallic acid substituents The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol formed primarily from the oxidative linkage of galloyl groups in 1,2,3,4,6-pentagalloyl glucose. Ellagitannins differ from gallotannins, in that their galloyl groups are linked through C-C bonds, whereas the galloyl groups in gallotannins are linked by depside bonds. Ellagitannins contain various numbers of Hexahydroxydiphenic acid, hexahydroxydiphenoyl units, as well as galloyl units and/or Sanguisorbic acid, sanguisorboyl units bounded to sugar moiety. In order to determine the quantity of every individual unit, the hydrolysis of the extracts with trifluoroacetic acid in methanol/water system is performed. Hexahydroxydiphenic acid, created after hydrolysis, spontaneously lactonized to ellagic acid, and sanguisorbic acid to sanguisorbic acid dilactone, while gallic acid remains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
