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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 en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terpene
Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes are further classified by the number of carbons: monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), as examples. The terpene alpha-pinene, is a major component of the common solvent, turpentine. History and terminology The term ''terpene'' was coined in 1866 by the German chemist August Kekulé to denote all hydrocarbons having the empirical formula C10H16, of which camphene was one. Previously, many hydrocarbons having the empirical formula C10H16 had been called "camphene", but many other hydrocarbons of the same composition had had different names. Kekulé coined the term "terpene" in order to reduce the confusion. The name "terpene" is a shortened form of "terpentine", an obsolete spelling of "turpentine". Although sometimes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patchoulol
Patchoulol or patchouli alcohol (C15H26O) is a sesquiterpene alcohol found in patchouli. Patchouli oil is an important material in perfumery. The (−)-optical isomer is one of the organic compounds responsible for the typical patchouli scent. Patchoulol is also used in the synthesis of the chemotherapy drug Taxol. Structure determination Patchouli alcohol was first isolated in 1869 by Gal and its chemical composition later correctly formulated as C15H26O by Montgolfier. During early structural investigation the presence of a saturated tricyclic tertiary alcohol was established. After several years of careful study Büchi and co-workers proposed the structure of patchouli alcohol to correspond to 1, based on degradation studies from his earlier work, verified later by synthesis of material which corresponded to the natural authentic sample of patchouli alcohol. A serendipitous finding by Dunitz and co-workers revealed a contradictory structure. They had undertaken an X-ray ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoterpenes
Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen functionality or missing a methyl group, are called monoterpenoids. Monoterpenes and monoterpenoids are diverse. They have relevance to the pharmaceutical, cosmetic, agricultural, and food industries. Biosynthesis Monoterpenes are derived biosynthetically from units of isopentenyl pyrophosphate, which is formed from acetyl-CoA via the intermediacy of mevalonic acid in the HMG-CoA reductase pathway. An alternative, unrelated biosynthesis pathway of IPP is known in some bacterial groups and the plastids of plants, the so-called MEP-(2-methyl-D-erythritol-4-phosphate) pathway, which is initiated from C5 sugars. In both pathways, IPP is isomerized to DMAPP by the enzyme isopentenyl pyrophosphate isomerase. Geranyl pyrophosphate is the precursor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caryophyllene
Caryophyllene (), more formally (−)-β-caryophyllene, (BCP), is a natural bicyclic sesquiterpene that is a constituent of many essential oils, especially clove oil, the oil from the stems and flowers of ''Syzygium aromaticum'' (cloves), the essential oil of ''Cannabis sativa'', rosemary, and hops. It is usually found as a mixture with isocaryophyllene (the ''cis'' double bond isomer) and α-humulene (obsolete name: α-caryophyllene), a ring-opened isomer. Caryophyllene is notable for having a cyclobutane ring, as well as a ''trans''-double bond in a 9-membered ring, both rarities in nature. β-Caryophyllene acts as a full agonist of the Cannabinoid receptor type 2 (CB2 receptor) in rats. β-Caryophyllene has a binding affinity of Ki = 155nM at the CB2 receptors in mice. β-Caryophyllene has been shown to have anti-inflammatory action linked to its CB2 receptor activity in a study comparing the pain killing effects in mice with and without CB2 receptors with the group of mice wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farnesol
Farnesol is a natural 15-carbon organic compound which is an acyclic sesquiterpene alcohol. Under standard conditions, it is a colorless liquid. It is hydrophobic, and thus insoluble in water, but miscible with oils. Farnesol is produced from 5-carbon isoprene compounds in both plants and animals. Phosphate-activated derivatives of farnesol are the building blocks of possibly all acyclic sesquiterpenoids. These compounds are doubled to form 30-carbon squalene, which is the precursor for steroids in plants, animals, and fungi. Farnesol and its derivatives are important starting compounds for natural and artificial organic synthesis. Uses Farnesol is present in many essential oils such as citronella, neroli, cyclamen, lemon grass, tuberose, rose, musk, balsam, and tolu. It is used in perfumery to emphasize the odors of sweet, floral perfumes. It enhances perfume scent by acting as a co-solvent that regulates the volatility of the odorants. It is especially used in lilac perf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farnesene
The term farnesene refers to a set of six closely related chemical compounds which all are sesquiterpenes. α-Farnesene and β-farnesene are isomers, differing by the location of one double bond. α-Farnesene is 3,7,11-trimethyl-1,3,6,10-dodecatetraene and β-farnesene is 7,11-dimethyl-3-methylene-1,6,10-dodecatriene. The alpha form can exist as four stereoisomers that differ about the geometry of two of its three internal double bonds (the stereoisomers of the third internal double bond are identical). The beta isomer exists as two stereoisomers about the geometry of its central double bond. Two of the α-farnesene stereoisomers are reported to occur in nature. (''E'',''E'')-α-Farnesene is the most common isomer. It is found in the coating of apples, and other fruits, and it is responsible for the characteristic green apple odour. Its oxidation by air forms compounds that are damaging to the fruit. The oxidation products injure cell membranes which eventually causes cell dea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guaiazulene
Guaiazulene, also azulon or 1,4-dimethyl-7-isopropylazulene, is a dark blue crystalline hydrocarbon. A derivative (chemistry), derivative of azulene, guaiazulene is a bicyclic sesquiterpene that is a constituent of some essential oils, mainly oil of guaiac and German chamomile, chamomile oil, which also serve as its commercial sources. Various soft corals also contain guaiazulene as a principal pigment. Its low melting point makes guaiazulene difficult to handle, in contrast to the crystalline nature of the parent azulene. The electronic structure (and colors) of guaiazulene and azulene are very similar. A similar structure Alismol is in a different oxidation state. Applications Guaiazulene is an Food and Drug Administration, U.S. FDA-approved cosmetic color additive. It – or its 3-sulfonate – is a component of some skin care products together with other skin soothing compounds such as allantoin. Guaiazulene has applications as a volatile dye with a known evaporation rate to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadinene
Cadinenes are a group of isomeric hydrocarbons that occur in a wide variety of essential oil-producing plants. The name is derived from that of the Cade juniper (''Juniperus oxycedrus'' L.), the wood of which yields an oil from which cadinene isomers were first isolated. Chemically, the cadinenes are bicyclic sesquiterpenes. The term ''cadinene'' has sometimes also been used in a broad sense to refer to any sesquiterpene with the so-called cadalane (4-isopropyl-1,6-dimethyldecahydronaphthalene) carbon skeleton. Because of the large number of known double-bond and stereochemical isomers, this class of compounds has been subdivided into four subclasses based on the relative stereochemistry at the isopropyl group and the two bridgehead carbon atoms. The name ''cadinene'' is now properly used only for the first subclass below, which includes the compounds originally isolated from cade oil. Only one enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zingiberene
Zingiberene is a monocyclic sesquiterpene that is the predominant constituent of the oil of ginger (''Zingiber officinale''), from which it gets its name. It can contribute up to 30% of the essential oils in ginger rhizomes. This is the compound that gives ginger its distinct flavoring. Biosynthesis Zingiberene is formed in the isoprenoid pathway from farnesyl pyrophosphate (FPP). FPP undergoes a rearrangement to give nerolidyl diphosphate. After the removal of pyrophosphate 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 o ..., the ring closes leaving a carbocation on the tertiary carbon attached to the ring. A 1,3-hydride shift then takes place to give a more stable allylic carbocation. The final step in the formation of zingiberene is the removal of the cyclic allylic proton and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humulene
Humulene, also known as α-humulene or α-caryophyllene, is a naturally occurring monocyclic sesquiterpene (C15H24), containing an 11-membered ring and consisting of 3 isoprene units containing three nonconjugated C=C double bonds, two of them being triply substituted and one being doubly substituted. It was first found in the essential oils of '' Humulus lupulus'' (hops), from which it derives its name. Humulene is an isomer of β-caryophyllene, and the two are often found together as a mixture in many aromatic plants. Occurrence Humulene is one of the components of the essential oil from the flowering cone of the hops plant, '' Humulus lupulus'', from which it derives its name. The concentration of humulene varies among different varieties of the plant but can be up to 40% of the essential oil. Humulene and its reaction products in the brewing process of beer gives many beers their “hoppy” aroma. Noble hop varieties have been found to have higher levels of humulene, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
