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Pyranocoumarins
Pyranocoumarins are a class of chemical compounds that have a core structure that consists of a pyran ring fused to a coumarin. As phytochemicals, pyranocoumarins are uncommon and found mainly the plant families Apiaceae and Rutaceae. For example, ''Citrus sinensis'' and ''Citrus limonia'' are sources of xanthyletin and seselin. In the biosyntheses of pyranocoumarins, the pyran ring is formed via the methylerythritol phosphate pathway and the coumarin is derived from the shikimate pathway. See also * Furanocoumarin References Pyrans Coumarins Heterocyclic compounds with 3 rings {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyran
In chemistry, pyran, or oxine, is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the location of the double bonds. In 2''H''-pyran, the saturated carbon is at position 2, whereas, in 4''H''-pyran, the saturated carbon is at position 4. 4''H''-Pyran was first isolated and characterized in 1962 via pyrolysis of 2-acetoxy-3,4-dihydro-2''H''-pyran. It was found too unstable, particularly in the presence of air. 4''H''-pyran easily disproportionates to the corresponding dihydropyran and the pyrylium ion, which is easily hydrolyzed in aqueous medium. Although the pyrans themselves have little significance in chemistry, many of their derivatives are important biological molecules, such as the pyranoflavonoids. The term pyran is also often applied to the saturated ring analog, which is more properly referred to as tetrahydrop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coumarin
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered heterocycle that shares two carbons with the benzene ring. It can be placed in the benzopyrone chemical class and considered as a lactone. Coumarin is a colorless crystalline solid with a sweet odor resembling the scent of vanilla and a bitter taste. It is found in many plants, where it may serve as a chemical defense against predators. By inhibiting synthesis of vitamin K, a related compound is used as the prescription drug warfarin – an anticoagulant – to inhibit formation of blood clots, deep vein thrombosis, and pulmonary embolism. Etymology Coumarin is derived from ''coumarou'', the French word for the tonka bean. The word ''tonka'' for the tonka bean is taken from the Galibi (Carib) tongue spoken by natives of French G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytochemical
Phytochemicals are chemical compounds produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals. The name comes . Some phytochemicals have been used as poisons and others as traditional medicine. As a term, ''phytochemicals'' is generally used to describe plant compounds that are under research with unestablished effects on health, and are not scientifically defined as essential nutrients. Regulatory agencies governing food labeling in Europe and the United States have provided guidance for industry to limit or prevent health claims about phytochemicals on food product or nutrition labels. Definition Phytochemicals are chemicals of plant origin. Phytochemicals (from Greek ''phyto'', meaning "plant") are chemicals produced by plants through primary or secondary metabolism. They generally have biological activity in the plant host and play a role in plant growth or defense against competitors, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apiaceae
Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus ''Apium'' and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,700 species in 434 generaStevens, P.F. (2001 onwards)Angiosperm Phylogeny Website Version 9, June 2008. including such well-known and economically important plants as ajwain, angelica, anise, asafoetida, caraway, carrot, celery, chervil, coriander, cumin, dill, fennel, lovage, cow parsley, parsley, parsnip and sea holly, as well as silphium, a plant whose identity is unclear and which may be extinct. The family Apiaceae includes a significant number of phototoxic species, such as giant hogweed, and a smaller number of highly poisonous species, such as poison hemlock, water hemlock, spotted cowbane, fool's parsley, and various species of water dropwort. Description Most Apiaceae are annual, biennial or perennial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rutaceae
The Rutaceae is a family, commonly known as the rueRUTACEAE in BoDD – Botanical Dermatology Database or family, of s, usually placed in the order . Species of the family generally have s that divide into four or five parts, usually w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus Sinensis
''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Lemon, lemons, grapefruits, pomelos, and lime (fruit), limes. The genus ''Citrus'' is native to South Asia, East Asia, Southeast Asia, Melanesia, and Australia (continent), Australia. Various citrus species have been used and domesticated by indigenous cultures in these areas since ancient times. From there its cultivation spread into Micronesia and Polynesia by the Austronesian expansion (c. 3000–1500 BCE); and to the Middle East and the Mediterranean (c. 1200 BCE) via the incense trade route, and onwards to Europe and the Americas. History Citrus plants are native to subtropical and tropical regions of Asia, Island Southeast Asia, Near Oceania, and northeastern Australia. Domestication of citrus species involved much hybridization and introgression, leaving much uncertainty ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus Limonia
Rangpur, ''Citrus'' × ''limonia'' or ''Citrus reticulata'' × ''medica'', sometimes called the rangpur lime, mandarin lime or lemandarin, is a hybrid between the mandarin orange and the citron. It is a citrus fruit with a very acidic taste and an orange peel and flesh. Common names Common names for this fruit include rangpur, the name of a city now in Bangladesh. Rangpur is also known in the Indian subcontinent as ''Sylhet lime'' (after another region also now in Bangladesh), ''surkh nimboo'', and ''sharbati''. It is known as a ''canton-lemon'' in South China, a ''hime-lemon'' in Japan, as ''limão-capeta'', ''limão-cravo'', ''limão-rosa'' or ''limão-galego'' in Brazil and Portugal (namely in the Azores), and ''mandarin-lime'' in the United States, and similarly ''limón-mandarina'' (lemon tangerine) in Costa Rica because of its shape and the way its skin is peeled. History ''Citrus'' × ''limonia'' was introduced into Florida in the late nineteenth century by Reasoner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylerythritol Phosphate Pathway
The non-mevalonate pathway—also appearing as the mevalonate-independent pathway and the 2-''C''-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathway—is an alternative metabolic pathway for the biosynthesis of the isoprenoid precursors isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). The currently preferred name for this pathway is the MEP pathway, since MEP is the first committed metabolite on the route to IPP. Isoprenoid precursor biosynthesis The classical mevalonate pathway (MVA pathway or HMG-CoA reductase pathway) is a metabolic pathway for the biosynthesis of isoprenoid precursors: IPP and DMAPP. The MVA pathway is present in most eukaryotes and some bacteria. IPP and DMAPP serve as the basis for the biosynthesis of isoprenoid (terpenoid) molecules used in processes as diverse as protein prenylation, cell membrane maintenance, the synthesis of hormones, protein anchoring and ''N''-glycosylation in all three dom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shikimate Pathway
The shikimate pathway (shikimic acid pathway) is a seven-step metabolic pathway used by bacteria, archaea, fungi, algae, some protozoans, and plants for the biosynthesis of folates and aromatic amino acids (tryptophan, phenylalanine, and tyrosine). This pathway is not found in animal cells. The seven enzymes involved in the shikimate pathway are DAHP synthase, 3-dehydroquinate synthase, 3-dehydroquinate dehydratase, shikimate dehydrogenase, shikimate kinase, EPSP synthase, and chorismate synthase. The pathway starts with two substrates, phosphoenol pyruvate and erythrose-4-phosphate, and ends with chorismate, a substrate for the three aromatic amino acids. The fifth enzyme involved is the shikimate kinase, an enzyme that catalyzes the ATP-dependent phosphorylation of shikimate to form shikimate 3-phosphate (shown in the figure below). Shikimate 3-phosphate is then coupled with phosphoenol pyruvate to give 5-enolpyruvylshikimate-3-phosphate via the enzyme 5-enolpyruvylshikimate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furanocoumarin
The furanocoumarins, or furocoumarins, are a class of organic chemical compounds produced by a variety of plants. Most of the plant species found to contain furanocoumarins belong to a handful of plant families. The families Apiaceae and Rutaceae include the largest numbers of plant species that contain furanocoumarins. The families Moraceae and Fabaceae include a few widely distributed plant species that contain furanocoumarins. Generally furanocoumarins are most abundant in plants that have flowered and in ripe seeds and fruits. (An exception is the common fig where furanocoumarins are found chiefly in the milky sap of the leaves and shoots but not the fruits. Cited in McGovern and Barkley 2000, section&nbsPhytophotodermatitis) During the early stages of plant growth, their presence is not easily detected. Structure The chemical structure of furanocoumarins consists of a furan ring fused with a coumarin. The furan ring may be fused in various ways producing several differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
