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Valencene
Valencene is a sesquiterpene that is an aroma component of citrus fruit and citrus-derived odorants. It is obtained inexpensively from Valencia oranges. Valencene is biosynthesized from farnesyl pyrophosphate (FPP) by the CVS enzyme. It is a precursor to nootkatone Nootkatone is a natural organic compound, a sesquiterpenoid, and a ketone that is the most important and expensive aromatic of grapefruit, and which also occurs in other organisms. Previously, nootkatone was thought to be one of the main chemic ..., the main contributor to the aroma and flavor of grapefruit and is often used in insecticides, cleaning, personal care products and cosmetics. References {{Terpenes Sesquiterpenes Decalins Alkene derivatives Cyclohexenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CVS (enzyme)
Valencene synthase (EC 4.2.3.73) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase (valencene-forming). It is a terpene cyclase enzyme responsible for the biosynthesis of valencene, a sesquiterpene, using farnesyl pyrophosphate as its substrate. The first such enzyme was isolated using orange cDNA. This enzyme catalyses the following chemical reaction : (2''E'',6''E'')-farnesyl diphosphate \rightleftharpoons (+)-valencene + diphosphate The recombinant enzyme from ''Vitis vinifera ''Vitis vinifera'', the common grape vine, is a species of flowering plant, native to the Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are curre ...'' forms (+)-valencene and (-)-7-''epi''-α-selinene. References External links * {{Portal bar, Biology, border=no EC 4.2.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nootkatone
Nootkatone is a natural organic compound, a sesquiterpenoid, and a ketone that is the most important and expensive aromatic of grapefruit, and which also occurs in other organisms. Previously, nootkatone was thought to be one of the main chemical components of the smell and flavour of grapefruits. In high purity, it usually is found as colorless crystals. Crude extractives are liquid, viscous, and yellow. Nootkatone typically is extracted from grapefruit through the chemical or biochemical oxidation of valencene. It is found in Alaska yellow cedar trees, as well as in vetiver grass. Mechanism of action As is true of other plant terpenoids, nootkatone activates α-adrenergic type 1 octopamine receptor (PaOA1) in susceptible arthropods, causing fatal spasms. Natural origin Nootkatone was isolated from the wood of the Alaskan yellow cedar, ''Cupressus nootkatensis''. The species name, nootkatensis, is derived from the language of the Nuu-Chah-Nulth people of Canada (formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids. Sesquiterpenes are found naturally in plants and insects, as semiochemicals, e.g. defensive agents or pheromones. Biosynthesis and examples The reaction of geranyl pyrophosphate with isopentenyl pyrophosphate results in the 15-carbon farnesyl pyrophosphate (FPP), which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene. Cyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors. In addition to common six-membered ring systems such as the ones found in zingiberene and bisacurone, cyclization of one end of the chain to the other end can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus
''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] |
Orange (fruit)
An orange is a fruit of various citrus species in the family (biology), family Rutaceae (see list of plants known as orange); it primarily refers to Citrus × sinensis, ''Citrus'' × ''sinensis'', which is also called sweet orange, to distinguish it from the related ''Citrus × aurantium'', referred to as bitter orange. The sweet orange reproduces asexually (apomixis through nucellar embryony); varieties of sweet orange arise through mutations. The orange is a Hybrid (biology), hybrid between pomelo (''Citrus maxima'') and Mandarin orange, mandarin (''Citrus reticulata''). The chloroplast genome, and therefore the maternal line, is that of pomelo. The sweet orange has had its full Whole genome sequencing, genome sequenced. The orange originated in a region encompassing Southern China, Northeast India, and Myanmar, and the earliest mention of the sweet orange was in Chinese literature in 314 BC. , orange trees were found to be the most Tillage, cultivated fruit tree in the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism. The prerequisite elements for biosynthesis include: precursor compounds, chemical energy (e.g. ATP), and catalytic enzymes which may require coenzymes (e.g.NADH, NADPH). These elements create monomers, the building blocks for macromolecules. Some important biological macromolecules include: proteins, which are composed of amino acid monomers joined via peptide bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farnesyl Pyrophosphate
Farnesyl pyrophosphate (FPP), also known as farnesyl diphosphate (FDP), is an intermediate in the biosynthesis of terpenes and terpenoids such as sterols and carotenoids. It is also used in the synthesis of CoQ (part of the electron transport chain), as well as dehydrodolichol diphosphate (a precursor of dolichol, which transports proteins to the ER lumen for ''N''-glycosylation). Biosynthesis Farnesyl pyrophosphate synthase (a prenyl transferase) catalyzes sequential condensation reactions of dimethylallyl pyrophosphate with 2 units of 3-isopentenyl pyrophosphate to form farnesyl pyrophosphate, as is shown in the following two steps: * Dimethylallyl pyrophosphate reacts with 3-isopentenyl pyrophosphate to form geranyl pyrophosphate: * Geranyl pyrophosphate then reacts with another molecule of 3-isopentenyl pyrophosphate to form farnesyl pyrophosphate Pharmacology The above reactions are inhibited by bisphosphonates (used for osteoporosis). Farnesyl pyrophosphate is a sel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grapefruit
The grapefruit (''Citrus'' × ''paradisi'') is a subtropical citrus tree known for its relatively large, sour to semi-sweet, somewhat bitter fruit. The interior flesh is segmented and varies in color from pale yellow to dark pink. Grapefruit is a citrus hybrid originating in Barbados. It is an accidental cross between the sweet orange (''C. sinensis'') and the pomelo or shaddock (''C. maxima''), both of which were introduced from Asia in the 17th century. It has also been called the ''forbidden fruit''. In the past it was referred to as the ''pomelo'', but that term is now mostly used as the common name for ''Citrus maxima''. In 2019, world production of grapefruits (combined with pomelos) was 9.3 million tonnes, of which 53% was in China. Other significant producers include Vietnam, United States and Mexico. Description The evergreen grapefruit trees usually grow to around tall, although they may reach . The leaves are long (up to ), thin, glossy, and dark green. They produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical & Engineering News
''Chemical & Engineering News'' (''C&EN'') is a weekly news magazine published by the American Chemical Society, providing professional and technical news and analysis in the fields of chemistry and chemical engineering.C&EN Magazine Website Chemical and Engineering News, October 12, 2009, accessed October 12, 2009 It includes information on recent news and research in these fields, career and employment information, business and industry news, government and policy news, funding in these fields, and special reports. The magazine is available to all members of the American Chemical Society. History The magazine was established in 1923,C&EN- Happy Birthday to Us, accessed O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sesquiterpenes
Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids. Sesquiterpenes are found naturally in plants and insects, as semiochemicals, e.g. defensive agents or pheromones. Biosynthesis and examples The reaction of geranyl pyrophosphate with isopentenyl pyrophosphate results in the 15-carbon farnesyl pyrophosphate (FPP), which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene. Cyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors. In addition to common six-membered ring systems such as the ones found in zingiberene and bisacurone, cyclization of one end of the chain to the other end can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkene Derivatives
In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, and Biological Chemistry'. 1232 pages. Two general types of monoalkenes are distinguished: terminal and internal. Also called α-olefins, terminal alkenes are more useful. However, the International Union of Pure and Applied Chemistry (IUPAC) recommends using the name "alkene" only for acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc. for cyclic ones; and "olefin" for the general class – cyclic or acyclic, with one or more double bonds. Acyclic alkenes, with only one double bond and no other functional groups (also known as mono-enes) form a homologous series of hydrocarbons with the general formula with '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
