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Stilbenes
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 fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astringin
Astringin is a stilbenoid, the 3-β-D-glucoside of piceatannol. It can be found in the bark of ''Picea sitchensis'' or ''Picea abies'' (Norway spruce). It is also present in ''Vitis vinifera'' cells cultures and in wine. See also *Phenolic compounds in wine The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include ... References Stilbenoid glycosides Phenol glucosides {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resveratrol
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 from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resveratrol
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 from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterostilbene
Pterostilbene () (trans-3,5-dimethoxy-4-hydroxystilbene) is a stilbenoid chemically related to resveratrol. In plants, it serves a defensive phytoalexin role. Natural occurrence Pterostilbene is found in almonds, various ''Vaccinium'' berries (including blueberries), grape leaves and vines, and ''Pterocarpus marsupium'' heartwood. Safety and regulation Pterostilbene is considered to be a corrosive substance, is dangerous upon exposure to the eyes, and is an environmental toxin, especially to aquatic life. A randomized, double-blind, placebo-controlled of healthy human subjects given pterostilbene for 6–8 weeks, showed pterostilbene to be safe for human use at dosages up to 250 mg per day. Its chemical relative, resveratrol, received FDA GRAS status in 2007, and approval of synthetic resveratrol as a safe compound by the European Food Safety Authority (EFSA) in 2016. Pterostilbene differs from resveratrol by exhibiting increased bioavailability (80% compared to 20% in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinosylvin
Pinosylvin is an organic compound with the formula C6H5CH=CHC6H3(OH)2. A white solid, it is related to trans-stilbene, but with two hydroxy groups on one of the phenyl substituents. It is very soluble in many organic solvents, such as acetone. Occurrence Pinosylvin is produced in plants in response to fungal infections, ozone-induced stress, and physical damage for example. It is a fungitoxin protecting the wood from fungal infection. It is present in the heartwood of ''Pinaceae'' and also found in '' Gnetum cleistostachyum''. Injected in rats, pinosylvin undergoes rapid glucuronidation and a poor bioavailability. Biosynthesis Pinosylvin synthase, an enzyme, catalyzes the biosynthesis of pinosylvin from malonyl-CoA and cinnamoyl-CoA: :3 malonyl-S-CoA + cinnamoyl-S-CoA → 4 CoA-SH + pinosylvin + 4 CO2 This biosynthesis is noteworthy because plant biosyntheses employing cinnamic acid as a starting point are rare compared to the more common use of ''p''-coumaric acid. Tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piceatannol
Piceatannol is the organic compound with the formula . Classified as a stilbenoid and a phenol, it is a white solid, although samples often are yellow owing to impurities. Natural occurrences Piceatannol and its glucoside, astringin, are found in mycorrhizal and non-mycorrhizal roots of Norway spruces (''Picea abies''). It can also be found in the seeds of the palm ''Aiphanes horrida'' and in '' Gnetum cleistostachyum''. The chemical structure of piceatannol was established by Cunningham et al. as being an analog of resveratrol. In food Piceatannol is a metabolite of resveratrol found in red wine, grapes, passion fruit, white tea, and Japanese knotweed. Astringin, a piceatannol glucoside, is also found in red wine. The formation of piceatannol from resveratrol is catalyzed by cytochrome P450. Biochemical study A 1989 ''in vitro'' study found that piceatannol blocked LMP2A, a viral protein-tyrosine kinase implicated in leukemia, non-Hodgkin's lymphoma and other diseases a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3,5-Dihydroxy-4-isopropyl-trans-stilbene
Tapinarof, also known as benvitimod and sold under the brand name Vtama, is a medication used for the treatment of plaque psoriasis. The medication is applied to the skin. Besides its use in medicine, tapinarof is a naturally occurring compound found in bacterial symbionts of nematodes which has antibiotic properties. The medication acts as an aryl hydrocarbon receptor agonist. Tapinarof was approved for medical use in the United States in May 2022. Medical uses Tapinarof is indicated for the treatment of plaque psoriasis in adults. Society and culture Names Tapinarof is the International Nonproprietary Name (INN). Natural occurrence Tapinarof, also known as benvitimod, is a bacterial stilbenoid produced in ''Photorhabdus'' bacterial symbionts of '' Heterorhabditis'' nematodes. It is a product of an alternative ketosynthase-directed stilbenoid biosynthesis pathway. It is derived from the condensation of two β-ketoacyl thioesters. It is produced by the ''Photorhabdus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterorhabditis
''Heterorhabditis'' is a genus of nematodes belonging to the order Rhabditida. All species of this genus are obligate parasites of insects, and some are used as biological control agents for the control of pest insects. ''Heterorhabditis'' nematodes are hosts for the '' Photorhabdus'' bacterial symbiont. Species The recognized species in this genus are: * ''Heterorhabditis amazonensis'' Andaló, Nguyen & Moino, 2007 * ''Heterorhabditis bacteriophora'' Poinar, 1976 * ''Heterorhabditis baujardi ''Heterorhabditis'' is a genus of nematodes belonging to the order Rhabditida. All species of this genus are obligate parasites of insects, and some are used as biological control agents for the control of pest insects. ''Heterorhabditis'' nemat ...'' Phan, Subbotin, Nguyen & Moens, 2003 * '' Heterorhabditis downesi'' Stock, Griffin & Burnell, 2002 * '' Heterorhabditis floridensis'' Nguyen, Gozel, Koppenhöfer & Adams, 2006 * '' Heterorhabditis georgiana'' Nguyen, Shapiro-Ilan and Mbata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photorhabdus
''Photorhabdus'' is a genus of bioluminescent, gram-negative bacilli which lives symbiotically within entomopathogenic nematodes, hence the name ''photo'' (which means light producing) and ''rhabdus'' (rod shape). ''Photorhabdus'' is known to be pathogenic to a wide range of insects and has been used as biopesticide in agriculture. Life cycle ''Photorhabdus'' species facilitate the reproduction of entomopathogenic nematodes by infecting and killing susceptible insect larvae. Entomopathogenic nematodes are normally found in soil. Nematodes infect larval hosts by piercing the larval cuticle. When the nematode enters an insect larvae, ''Photorhabdus'' species are released by the nematodes and will produce a range of toxins, killing the host within 48 hours. ''Photorhabdus'' species feed on the cadaver of the insect and the process converts the cadaver into a nutrient source for the nematode. Mature nematodes leave the depleted body of the insect and search for new hosts to infec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angew Chem Int Ed Engl
''Angewandte Chemie'' (, meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker). Publishing formats include feature-length reviews, short highlights, research communications, minireviews, essays, book reviews, meeting reviews, correspondences, corrections, and obituaries. This journal contains review articles covering all aspects of chemistry. According to the ''Journal Citation Reports'', the journal had a 2021 impact factor of 16.823. Editions The journal appears in two editions with separate volume and page numbering: a German edition, ''Angewandte Chemie'' ( (print), (online)), and a fully English-language edition, ''Angewandte Chemie International Edition'' ( (print), (online)). The editions are identical in content with the exception of occasional reviews of German-language books or German translations of IUPAC recommendations. Business model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolite
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the normal growth, development, or reproduction of the organism. Instead, they generally mediate ecological interactions, which may produce a selective advantage for the organism by increasing its survivability or fecundity. Specific secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory and other interspecies defenses. Humans use secondary metabolites as medicines, flavourings, pigments, and recreational drugs. The term secondary metabolite was first coined by Albrecht Kossel, a 1910 Nobel Prize laureate for medicine and physiology in 1910. 30 years later a Polish botanist Friedrich Czapek described secondary metabolit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
