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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'', the Valonia oak, is a species of oak in the beech family, Fagaceae. Formerly, it was commonly treated as a subspecies of the closely related and sympatric mount Tabor oak. At present, however, it is mostly granted speci ... (''Quercus macrolepis'') * Valoneic acid dilactone References External links Plant polyphenols: vegetable tannins revisited, page 136by Edwin Haslam Ellagitannins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysable Tannin
A hydrolyzable 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 hydrolyzable 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. Hydrolyzable tannins are hydrolyzed 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 (''Castanea ... [...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 plants ... 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. 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 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 ... Re ... [...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. left, 142px, Ellagic acid. Hexahydroxydiphenic acid is a component of some ellagitannins, such as casuarictin. Luteic acid is the monolactone and ellagic acid is the dilactone Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring. Lactones are formed by intramolecular esterification of the co ... of hexahydroxydiphenic acid. See also * Diphenic acid References Ellagitannins Pyrogallols Biphenyls Hydroxybenzoic 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". 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 shikimate dehydrogenase to produce 3,5-didehydroshikimate. This latter compound aromatizes. Reactions Oxidation and oxidative coupling Alkaline solutions of ... [...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 References External links Plant polyphenols: vegetable tannins revisited, page 136by Edwin Haslam Edwin Haslam (1932 – 3 October 2013) [...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. 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 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 ... Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valonea
''Quercus macrolepis'', the Valonia oak, is a species of oak in the beech family, Fagaceae. Formerly, it was commonly treated as a subspecies of the closely related and Sympatry, sympatric Quercus ithaburensis, mount Tabor oak. At present, however, it is mostly granted species-status. Geographical range It is found in the Balkans, and in the southern and eastern Mediterranean, including Albania, the Greek Islands, Turkey, Israel, and Morocco. Systematics Within the oak genus, Quercus macrolepis is classified in the List of Quercus species#Subgenus Cerris, subgenus ''Cerris'', List of Quercus species#Section Cerris, section ''Cerris'', which includes the Quercus cerris, turkey oak and related species. It is most closely related to Mount Tabor oak (Quercus ithaburensis) and Quercus brantii, Brant's oak (Quercus brantii). Uses The cups, known as valonia, are used for Tanning (leather), tanning and dyeing as are the unripe acorns called camata or camatina. The ripe acorns are e ... [...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'').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 5α-reductase inhibitor, inhibitory effect on 5α-reductase, an enzyme involved in steroids metabolism and prostate cancer. References External links * Ellagitannins 5α-Reductase inhibitors Lactones Trihydroxybenzoic acids {{aromatic-stub ... [...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 . Haslam proposed a first comprehensive definition of plant polyphenols based on the earlier proposals of [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellagitannins
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 hexahydroxydiphenoyl units, as well as galloyl units and/or 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 intact. Ellagitannins generally form macrocycles, whereas gallotannins do not. Examples * Castalagin * Castalin * Casuarictin * Grandinin * Oenothein B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
