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Roburin A
Roburin A is a tannin found in oak wood (''Quercus robur'' and ''Quercus petraea'' or ''Quercus alba'') or oak cork (''Quercus suber''). It is a dimeric compound, composed of two vescalagin 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 ... subunits probably linked through an ether bond between the diphenoyl group ( hexahydroxydiphenic acid or HHDP) of one subunit and the triphenoyl moiety ( nonahydroxytriphenic acid) of the other one. References Ellagitannins Tannin dimers {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quercus Robur
''Quercus robur'', commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native to most of Europe west of the Caucasus. It is widely cultivated in temperate regions elsewhere and has escaped into the wild in scattered parts of China and North America. Description ''Quercus robur'' is a large deciduous tree, with circumference of grand oaks from to an exceptional . The Majesty Oak with a circumference of is the thickest tree in Great Britain. The Brureika (Bridal Oak) in Norway with a circumference of (2018) and the Kaive Oak in Latvia with a circumference of are among the thickest trees in Northern Europe. The largest historical oak was known as the Imperial Oak from Bosnia and Herzegovina. This specimen was recorded at 17.5 m in circumference at breast height and estimated at over 150 m³ in total volume. It collapsed in 1998. The species has lobed and nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quercus Petraea
''Quercus petraea'', commonly known as the sessile oak, Cornish oak, Irish Oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland, and an unofficial emblem in Wales and Cornwall. Description The sessile oak is a large deciduous tree up to tall, in the white oak section of the genus (''Quercus'' sect. ''Quercus'') and similar to the pedunculate oak (''Q. robur''), with which it overlaps extensively in range. The leaves are long and broad, evenly lobed with five to six lobes on each side and a petiole. The male flowers are grouped into catkins, produced in the spring. The fruit is an acorn long and broad, which matures in about six months. Comparison with pedunculate oak Significant botanical differences from pedunculate oak (''Q. robur'') include the stalked leaves, and the stalkless (sessile) acorns from which one of its common names is derived. It occurs in up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quercus Alba
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably '' Lithocarpus'' (stone oaks), as well as in those of unrelated species such as '' Grevillea robusta'' (silky oaks) and the Casuarinaceae (she-oaks). The genus ''Quercus'' is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa. North America has the largest number of oak species, with approximately 160 species in Mexico of which 109 are endemic and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species. Description Oaks have spirally arranged leaves, with lobate margins in many species; some have serrated leaves or entire leaves with smooth ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quercus Suber
''Quercus suber'', commonly called the cork oak, is a medium-sized, evergreen oak tree in the section ''Quercus'' sect. ''Cerris''. It is the primary source of cork for wine bottle stoppers and other uses, such as cork flooring and as the cores of cricket balls. It is native to southwest Europe and northwest Africa. In the Mediterranean basin the tree is an ancient species with fossil remnants dating back to the Tertiary period. It endures drought and makes little demand on the soil quality and is regarded as a defence against desertification. Cork oak forests are home to a multitude of animal and plant species. Since cork is increasingly being displaced by other materials as a bottle cap, these forests are at risk as part of the cultural landscape and animal species such as the Iberian lynx are threatened with extinction. Description General appearance and bark The cork oak grows as an evergreen tree, reaching an average height of or in rare cases up to 25 m and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vescalagin
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 glycosidic chain. Castalagin/ vescalagin are the most abundant ellagitannins in white wine stored in oak barrels. During aging of wines, these two compounds were progressively extracted from the wood and were transformed into new derivatives by chemical reactions. Therefore, castalagin/ vescalagin and their derivatives contribute to the color and the taste of wines and spirits stored in oak barrels. Sources Castalagin was first isolated in Fagaceae family woody species : ''Quercus'' (oak) and ''Castanea'' (chestnut) by Walter Mayer and co-workers (1967). In some chestnut species, such as ''Castanea sativa'', heartwood could contain 63 mg of castalagin/ vescalagin per gram of dry wood. In some wines, these two isomers represent about 40 to 70 ... [...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] |
Nonahydroxytriphenic Acid
Nonahydroxytriphenic acid is a moiety found in some ellagitannins such as roburin A, B,C and D, 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 ... or grandinin.Roburin A, a dimeric ellagitannin from heartwood of Quercus robur. Hervé Du Penhoat, Michon V. M. F., Ohassan A., Shuyun Peng, Scalbert A. and Gage D., Phytochemistry, 1991, vol. 30, no 1, pages 329-332, References Ellagitannins Tricarboxylic acids {{aromatic-stub ... [...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] |
