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(S)-beta-bisabolene
Bisabolenes are a group of closely related natural chemical compounds which are classified as sesquiterpenes. Bisabolenes are produced from farnesyl pyrophosphate (FPP) and are present in the essential oils of bisabol, and of a wide variety of other plants including cubeb, lemon, and oregano. Various derivates also function as pheromones in different insects, such as stink bugs and fruit flies. Bisabolenes are produced by several fungi, though their biological role in that group of organisms remains unclear. Three isomers are known, α-, β-, and γ-bisabolene, which differ by the positions of the double bonds. Uses Bisabolenes are intermediates in the biosynthesis of many other natural chemical compounds, including hernandulcin, a natural sweetener. β-Bisabolene has a balsamic odor and is approved in Europe as a food additive. Bisabolene has been identified as a biologically producible precursor to a diesel fuel alternative and/or cold weather additive bisabol''ane'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(S)-beta-bisabolene Synthase
(''S'')-β-bisabolene synthase (EC 4.2.3.55) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase ((''S'')-β-bisabolene-forming). This enzyme catalyses the following chemical reaction : (2''E'',6''E'')-farnesyl diphosphate \rightleftharpoons (''S'')-β-bisabolene + diphosphate In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among othe ... The synthesis of (''S'')-β-macrocarpene from (2''E'',6''E'')-farnesyl diphosphate proceeds in two steps. References External links * {{Portal bar, Biology, border=no EC 4.2.3 ... [...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] |
Double Bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist between two different elements: for example, in a carbonyl group between a carbon atom and an oxygen atom. Other common double bonds are found in azo compounds (N=N), imines (C=N), and sulfoxides (S=O). In a skeletal formula, a double bond is drawn as two parallel lines (=) between the two connected atoms; typographically, the equals sign is used for this. Double bonds were first introduced in chemical notation by Russian chemist Alexander Butlerov. Double bonds involving carbon are stronger and shorter than single bonds. The bond order is two. Double bonds are also electron-rich, which makes them potentially more reactive in the presence of a strong electron acceptor (as in addition reactions of the halogens). File:Ethene structural.svg ... [...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] |
National Institute Of Standards And Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards. History Background The Articles of Confederation, ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of the Constitution of the United States, ratified in 1789, granted these powers to the new Congr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(Z)-gamma-bisabolene Synthase
(''Z'')-γ-bisabolene synthase (EC 4.2.3.40) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase ((''Z'')-γ-bisabolene-forming). This enzyme catalyses the following chemical reaction : (2''E'',6''E'')-farnesyl-diphosphate diphosphate \rightleftharpoons (''Z'')-γ-bisabolene + diphosphate This enzyme is expressed in the root, hydathodes and stigma of the plant ''Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small flowering plant native to Eurasia and Africa. ''A. thaliana'' is considered a weed; it is found along the shoulders of roads and in disturbed land. A winter a ...''. References External links * {{Portal bar, Biology, border=no EC 4.2.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(E)-gamma-bisabolene Synthase
(''E'')-γ-bisabolene synthase (EC 4.2.3.59) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase ((''E'')-γ-bisabolene-forming). This enzyme catalyses the following chemical reaction : (2''E'',6''E'')-farnesyl diphosphate \rightleftharpoons (''E'')-γ-bisabolene + diphosphate In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among othe ... References External links * {{Portal bar, Biology, border=no EC 4.2.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-bisabolene Synthase
α-Bisabolene synthase (EC 4.2.3.38, bisabolene synthase) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase ((''E'')-α-bisabolene-forming). This enzyme catalyses the following chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ... : (2''E'',6''E'')-farnesyl diphosphate \rightleftharpoons (''E'')-α-bisabolene + diphosphate This synthase requires a divalent cation cofactor (Mg2+ or, to a lesser extent, Mn2+) to neutralize the negative charge of the diphosphate leaving group. References External links * {{Portal bar, Biology, border=no EC 4.2.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Fuel
Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and then injection of fuel. Therefore, diesel fuel needs good compression ignition characteristics. The most common type of diesel fuel is a specific fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is sometimes called petrodiesel in some academic circles. In many countries, diesel fuel is standardised. For example, in the European Union, the standard for diesel fuel is EN 590. Diesel fuel has many colloquial names; most commonly, it is simply referred to as ''diesel''. In the United Kingdom, diesel fuel for on-road use is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hernandulcin
Hernandulcin is an intensely sweet chemical compound gained from the chiefly Mexican and South American plant ''Lippia dulcis''. History and origin In the 1570s, Spanish physician Francisco Hernández described a remarkably sweet plant known to the Aztecs as Tzonpelic xihuitl, meaning "sweet herb". This reference, accompanied by an accurate description and illustration of the plant, led to a group of pharmacognocists in 1985 to a previously unrecognised, intensely sweet chemical that can provide sweetness without tooth decay. Cesar M. Compadre, and A. Douglas Kinghorn, from the University of Illinois at Chicago isolated and identified the sweet compound from the leaves and flowers of the ''Lippia dulcis'' plant, in Mexico. The researchers noted the chemical structure of the colourless oil, and named it hernandulcin after Francisco Hernandez. Structure Hernandulcin is a sesquiterpene with the molecular formula C15H24O2. By slightly modifying the compound, researchers have i ... [...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] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which ''bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a back-for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
