|
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] |
Ellagitannin
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 from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambertianin C
Lambertianin C is an ellagitannin. Natural occurrence Lambertianin C can be found in ''Rubus'' species such as '' Rubus lambertianus'', in cloudberries (''Rubus chamaemorus'') and in red raspberries (''Rubus idaeus''). Chemistry Lambertianin C is trimer of casuarictin linked by 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 hydr ... ester groups between glucopyranose moieties. It contributes to the antioxidant capacity of raspberries. References External links Lambertianin C at www.phenol-explorer.eu {{Ellagitannin Ellagitannins Natural phenol trimers Rubus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catechols
Catechol ( or ), also known as pyrocatechol or 1,2-dihydroxybenzene, is a toxic organic compound with the molecular formula . It is the ''ortho'' isomer of the three isomeric benzenediols. This colorless compound occurs naturally in trace amounts. It was first discovered by destructive distillation of the plant extract catechin. About 20,000 tonnes of catechol are now synthetically produced annually as a commodity organic chemical, mainly as a precursor to pesticides, flavors, and fragrances. Catechol occurs as feathery white crystals that are very rapidly soluble in water. Isolation and synthesis Catechol was first isolated in 1839 by Edgar Hugo Emil Reinsch (1809–1884) by distilling it from the solid tannic preparation catechin, which is the residuum of catechu, the boiled or concentrated juice of ''Mimosa catechu'' (''Acacia catechu''). Upon heating catechin above its decomposition point, a substance that Reinsch first named ''Brenz-Katechusäure'' (burned catechu acid) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydroxybenzoic Acids
Dihydroxybenzoic acids (DHBA) are a type of phenolic acids. There are six main compounds, having all the same molecular formula C7H6O4. Those are: * 2,3-Dihydroxybenzoic acid (2-Pyrocatechuic acid or hypogallic acid) * 2,4-Dihydroxybenzoic acid (β-Resorcylic acid) * 2,5-Dihydroxybenzoic acid (Gentisic acid) * 2,6-Dihydroxybenzoic acid (γ-Resorcylic acid) * 3,4-Dihydroxybenzoic acid (Protocatechuic acid) * 3,5-Dihydroxybenzoic acid (α-Resorcylic acid) Orsellinic acid Orsellinic acid, more specifically ''o''-orsellinic acid, is a phenolic acid. It is of importance in the biochemistry of lichens, from which it can be extracted. It is a common subunit of depsides. Chemistry It can be prepared by the oxi ... is also a dihydoxybenzoic acid having an extra methyl group. {{Chemistry index Dihydroxybenzoic acids ... [...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 from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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] |
Rubus Lambertianus
''Rubus lambertianus'' is a flowering plant species in the genus ''Rubus'' found in Southern China (including Hainan), Taiwan, Japan, and Thailand. Its ploidy is 2''n'' = 4X (tetraploid). The ellagitannins lambertianin A, B, C and D can be found in ''R. lambertianus''. Description ''Rubus lambertianus'' is a lianoid, semi-deciduous Semi-deciduous or semi-evergreen is a botanical term which refers to plants that lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and sub-tropical woody spe ... shrub that can grow tall. Flowers are white and in diameter. Mature berries are red and in diameter. In China, it occurs on slopes, roadsides, montane valleys, stony ravines, grasslands, thickets, sparse forests, and forest margins at elevations of asl. In Taiwan it is common in thickets at medium elevations. References External links * * {{Taxonbar, from=Q7376211 lambertianus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambertianin D
Lambertianin D is an ellagitannin found in ''Rubus lambertianus''. It is tetramer of casuarictin linked by 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 hydr ... ester groups between glucopyranose moieties. References Ellagitannins Natural phenol tetramers {{aromatic-stub ... [...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] |
