|
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] |
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] |
Tetramer (chemistry)
A tetramer () (''tetra-'', "four" + ''-mer'', "parts") is an oligomer formed from four monomers or subunits. The associated property is called ''tetramery''. An example from inorganic chemistry is titanium methoxide with the empirical formula Ti(OCH3)4, which is tetrameric in solid state and has the molecular formula Ti4(OCH3)16. An example from organic chemistry is kobophenol A, a substance that is formed by combining four molecules of resveratrol. In biochemistry, it similarly refers to a biomolecule formed of four units, that are the same ( homotetramer), i.e. as in Concanavalin A or different (heterotetramer), i.e. as in hemoglobin. Hemoglobin has 4 similar sub-units while immunoglobulins have 2 very different sub-units. The different sub-units may have each their own activity, such as binding biotin in avidin tetramers, or have a common biological property, such as the allosteric binding of oxygen in hemoglobin. See also * Cluster chemistry; atomic and molecular clu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casuarictin
Casuarictin is an ellagitannin, a type of hydrolysable tannin. It can be found in ''Casuarina'' and ''Stachyurus'' species.Tannins of Casuarina and Stachyurus species. I: Structures of pendunculagin, casuarictin, strictinin, casuarinin, casuariin, and stachyurin. Okuda T., Yoshida T., Ashida M. and Yazaki K., Journal of the Chemical Society, 1983, number 8, pages 1765-1772, It is formed from two hexahydroxydiphenic acid units and one gallic acid unit linked to a glucose molecule. The molecule is formed from tellimagrandin II, itself formed from pentagalloyl glucose via oxidation. Casuarictin is transformed into pedunculagin via loss of a gallate group, and further into castalagin Castalagin is an ellagitannin, a type of hydrolyzable tannin, found in oak and chestnut wood and in the stem barks of '' Anogeissus leiocarpus'' and ''Terminalia avicennoides''. Castalagin is the diastereomer of vescalagin in C-1 of the glycosidi ... via glucose pyranose ring opening. Oligomers Sa ... [...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] |
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] |
