Delta-viniferin
δ-Viniferin is a resveratrol dehydrodimer (chemistry), dimer. It is an isomer of epsilon-viniferin. It can be isolated from stressed grapevine (''Vitis vinifera'') leaves. It is also found in plant cell cultures and wine. It can also be found in ''Rheum maximowiczii''. It is a grapevine phytoalexin following stresses like Fungal infection in plants, fungal infection (by ''Plasmopara viticola'', the agent of downy mildew), UV light irradiation or ozone treatment. ''Botryosphaeria obtusa'', a pathogen responsible for the black dead arm disease of grapevine, has also been shown to be able to oxidise wood δ-resveratrol into delta-viniferin. In cell cultures, the use of methyl jasmonate and jasmonic acid as elicitors stimulates δ-viniferin biosynthesis. Delta-viniferin can also be produced from resveratrol by human PTGS1 (COX-1, cyclooxygenase-1) or from ''trans''-resveratrol and (−)-epsilon-viniferin by horseradish peroxidase. See also * Phenolic content in wine * Viniferin ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Vitis Vinifera
''Vitis vinifera'', the common grape vine, is a species of flowering plant, native to the Mediterranean Basin, Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are currently between List of grape varieties, 5,000 and 10,000 varieties of ''Vitis vinifera'' grapes though only a few are of commercial significance for wine and table grape production. The wild grape is often classified as ''Vitis vinifera'' ''sylvestris'' (in some classifications considered ''Vitis sylvestris''), with ''Vitis vinifera'' ''vinifera'' restricted to cultivated forms. Domesticated vines have hermaphrodite#Botany, hermaphrodite flowers, but ''sylvestris'' is plant sexuality, dioecious (male and female flowers on separate plants) and pollination is required for fruit to develop. Grapes can be eaten fresh or dried to produce raisins, Sultana (grape)#Raisins, sultanas, and Zante currant, currants. Grape leaves ar ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Phytoalexins
Phytoalexins are antimicrobial substances, some of which are antioxidative as well. They are defined, not by their having any particular chemical structure or character, but by the fact that they are defensively synthesized ''de novo'' by plants that produce the compounds rapidly at sites of pathogen infection. In general phytoalexins are broad spectrum inhibitors; they are chemically diverse, and different chemical classes of compounds are characteristic of particular plant taxa. Phytoalexins tend to fall into several chemical classes, including terpenoids, glycosteroids and alkaloids, however the term applies to any phytochemicals that are induced by microbial infection. Function Phytoalexins are produced in plants to act as toxins to the attacking organism. They may puncture the cell wall, delay maturation, disrupt metabolism or prevent reproduction of the pathogen in question. Their importance in plant defense is indicated by an increase in susceptibility of plant tissue to ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Botryosphaeria Obtusa
''Botryosphaeria obtusa'' is a plant pathogen that causes frogeye leaf spot, black rot and cankers on many plant species. On the leaf it is referred to as frogeye leaf spot; this phase typically affects tree and shrubs. In fruit such as the apple, cranberry and quince, it is referred to as black rot, and in twigs and trunks it causes cankers. Symptoms Black rot ''Botryosphaeria obtusa'' enters the fruit through wounds. These can be made by insects, birds or growth cracks. At first a brown spot, near the calyx, appears on the fruit. The spot on the fruit then enlarges and black/brown rings appear on the fruit. The fruit holds its shape, however, unlike other fruit diseases. The fruit will then wither up and can remain on the tree for another year before falling off. During this time pycnidia appear on the surface of the rotted fruit. Frogeye leaf spot In leaves the fungus begins by causing purple specks on infected leaves. These then enlarge to cause large spots on the leaf, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Dimer (chemistry)
A dimer () (''di-'', "two" + ''-mer'', "parts") is an oligomer consisting of two monomers joined by bonds that can be either strong or weak, covalent or intermolecular. Dimers also have significant implications in polymer chemistry, inorganic chemistry, and biochemistry. The term ''homodimer'' is used when the two molecules are identical (e.g. A–A) and ''heterodimer'' when they are not (e.g. A–B). The reverse of dimerization is often called dissociation. When two oppositely charged ions associate into dimers, they are referred to as ''Bjerrum pairs'', after Niels Bjerrum. Noncovalent dimers Anhydrous carboxylic acids form dimers by hydrogen bonding of the acidic hydrogen and the carbonyl oxygen. For example, acetic acid forms a dimer in the gas phase, where the monomer units are held together by hydrogen bonds. Under special conditions, most OH-containing molecules form dimers, e.g. the water dimer. Excimers and exciplexes are excited structures with a short life ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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PTGS1
Cyclooxygenase 1 (COX-1), also known as prostaglandin G/H synthase 1, prostaglandin-endoperoxide synthase 1 or prostaglandin H2 synthase 1, is an enzyme that in humans is encoded by the ''PTGS1'' gene. In humans it is one of two cyclooxygenases. History Cyclooxygenase (COX) is the central enzyme in the biosynthetic pathway to prostaglandins from arachidonic acid. This protein was isolated more than 40 years ago and cloned in 1988. Gene and isozymes There are two isozymes of COX encoded by distinct gene products: a constitutive COX-1 (this enzyme) and an inducible COX-2, which differ in their regulation of expression and tissue distribution. The expression of these two transcripts is differentially regulated by relevant cytokines and growth factors. This gene encodes COX-1, which regulates angiogenesis in endothelial cells. COX-1 is also involved in cell signaling and maintaining tissue homeostasis. A splice variant of COX-1 termed COX-3 was identified in the central nervous ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Stilbenoid Dimers
Stilbenoids are hydroxylated derivatives of stilbene. They have a C6–C2–C6 structure. In biochemical terms, they belong to the family of phenylpropanoids and share most of their biosynthesis pathway with chalcones. Most stilbenoids are produced by plants, and the only known exception is the antihelminthic and antimicrobial stilbenoid, 2-isopropyl-5- ''E'')-2-phenylvinylenzene-1,3-diol, biosynthesized by the Gram-negative bacterium ''Photorhabdus luminescens.'' Chemistry Stilbenoids are hydroxylated derivatives of stilbene and have a C6–C2–C6 structure. They belong to the family of phenylpropanoids and share most of their biosynthesis pathway with chalcones. Under UV irradiation, stilbene and its derivatives undergo intramolecular cyclization, called stilbene photocyclization to form dihydrophenanthrenes. Oligomeric forms are known as oligostilbenoids. Types ;Aglycones * Piceatannol in the roots of Norway spruces * Pinosylvin is a fungal toxin protecting wood from ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Resveratrol Oligomers
Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacteria or fungi. Sources of resveratrol in food include the skin of grapes, blueberries, raspberries, mulberries, and peanuts. Although commonly used as a dietary supplement and studied in laboratory models of human diseases, there is no high-quality evidence that resveratrol improves lifespan or has a substantial effect on any human disease. Research Resveratrol has been studied for its potential therapeutic use, with little evidence of anti-disease effects or health benefits in humans. Cardiovascular disease There is no evidence of benefit from resveratrol in people who already have heart disease. A 2018 meta-analysis found no effect on systolic or diastolic blood pressure; a sub-analysis revealed a 2 mmHg decrease in systolic pressure only ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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R2-Viniferin
Vitisin A is a resveratrol tetramer found in plants of the genus ''Vitis''. It is a complex of two resveratrol dimers, (+)- epsilon-viniferin and ampelopsin B. It shows an opposite effect to hopeaphenol Hopeaphenol is a stilbenoid. It is a resveratrol tetramer. It has been first isolated from Dipterocarpaceae like '' Shorea ovalis''. It has also been isolated from wines from North Africa. It shows an opposite effect to vitisin A on apoptosis of ... on apoptosis of myocytes isolated from adult rat heart. References External links Website of the Schröder group Resveratrol oligomers Natural phenol tetramers Grape {{aromatic-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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R-Viniferin
Vitisin B is a resveratrol tetramer found in plants of the genus ''Vitis ''Vitis'' (grapevine) is a genus of 79 accepted species of vining plants in the flowering plant family Vitaceae. The genus is made up of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, ...''.Opposite Effects of Two Resveratrol (trans-3,5,4′-Trihydroxystilbene) Tetramers, Vitisin A and Hopeaphenol, on Apoptosis of Myocytes Isolated from Adult Rat Heart. Kazuhiko Seya, Kouta Kanemaru, Chiharu Sugimoto, Megumi Suzuki, Teruko Takeo, Shigeru Motomura, Haruo Kitahara, Masatake Niwa, Yoshiteru Oshima and Ken-Ichi Furukawa, JPET January 2009 vol. 328 no. 1 90-98, References External links Vitisin B on www.chemindustry.com Resveratrol oligomers Natural phenol tetramers Grape varieties {{aromatic-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Alpha-Viniferin
α-Viniferin is a stilbene trimer. It can be isolated from '' Caragana chamlagu'' and from ''Caragana sinica'' and from the stem bark of ''Dryobalanops aromatica''. It is also present in relation to resistance to ''Botrytis cinerea'' and ''Plasmopara viticola'' in ''Vitis vinifera'' and ''Vitis riparia''.Disease resistance of Vitis spp. and the production of the stress metabolites resveratrol, epsilon -viniferin, alpha -viniferin and pterostilbene. Langcake P, Physiological Plant Pathology, 1981, Vol. 18, No. 2, pages 213-226abstract) It has been shown to inhibit acetylcholinesterase Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acety .... References Resveratrol oligomers Acetylcholinesterase inhibitors {{Aromatic-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |