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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 combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids. It is estimated (2006) that 3000 sesquiterpenes have been identified. 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 lead to macrocyclic rings such as humulene. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zingiberene
Zingiberene is a cyclic compound, 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 oil, essential oils in ginger Rhizome, 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, 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 consequent formation of a double bond. Zingiberene synthase is the enzyme responsible for catalyzing the reaction forming zingiberene as well as other mono- and sesquiterpenes. See also * Gingerol * sequiphellandre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copaene
Copaene, or more precisely, α-copaene, is the common (or trivial) chemical name of an oily liquid hydrocarbon that is found in a number of essential oil-producing plants. The name is derived from that of the resin-producing tropical copaiba tree, '' Copaifera langsdorffii'', from which the compound was first isolated in 1914. Its structure, including the chirality, was determined in 1963. The double-bond isomer with an exocyclic- methylene group, β-copaene, was first reported in 1967. Chemically, the copaenes are tricyclic sesquiterpenes. The molecules are chiral, and the α-copaene enantiomer most commonly found in higher plants exhibits a negative optical rotation of about −6°. The rare (+)-α-copaene is also found in small amounts in some plants. (+)-α-copaene is of economic significance because it is strongly attracting to an agricultural pest, the Mediterranean fruit fly ''Ceratitis capitata ''Ceratitis capitata'', commonly known as the Mediterranean fruit fly or med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vetivazulene
Vetivazulene is an azulene derivate obtained from vetiver oil. It is a bicyclic sesquiterpene and an isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ... of guaiazulene. References Azulenes Sesquiterpenes {{hydrocarbon-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zingiberene
Zingiberene is a cyclic compound, 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 oil, essential oils in ginger Rhizome, 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, 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 consequent formation of a double bond. Zingiberene synthase is the enzyme responsible for catalyzing the reaction forming zingiberene as well as other mono- and sesquiterpenes. See also * Gingerol * sequiphellandre ... [...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 obtained by fermentation of leaves of ''Pogostemon cablin''. Patchoulol is also used in the synthesis of the chemotherapy drug Taxol. Structure determination Gal first isolated patchouli alcohol in 1869, and Montgolfier later formulated its chemical composition (correctly) as C15H26O. Early structural investigation soon established the presence of a saturated tricyclic tertiary alcohol. After several years of careful degradation study, George Büchi, Büchi and co-workers proposed that patchouli alcohol had the structure 1. A subsequent synthesis of material which corresponded to an authentic sample of natural patchouli alcohol appeared to verify Büchi's proposal. However, Jack D. Dunitz, Dunitz and co-workers serendipitou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longifolene
Longifolene is a common sesquiterpene. It is an oily liquid hydrocarbon found primarily in the high-boiling fraction of certain pine resins. The name is derived from that of a pine species from which the compound was isolated. It is a tricyclic chiral molecule. The enantiomer commonly found in pines and other higher plants exhibits a positive optical rotation of +42.73°. The other enantiomer (optical rotation −42.73°) is found in small amounts in certain fungi and liverworts. Occurrence Terpentine obtained from ''Pinus longifolia'' (obsolete name for ''Pinus roxburghii'' Sarg.) contains as much as 20% of longifolene. Longifolene is also one of two most abundant aroma constituents of lapsang souchong tea, because the tea is smoked over pinewood fires. Biosynthesis The biosynthesis of longifolene begins with farnesyl diphosphate (1) (also called farnesyl pyrophosphate) by means of a cationic polycyclization cascade. Loss of the pyrophosphate group and cyclization by the dist ... [...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 of azulene, guaiazulene is a bicyclic sesquiterpene that is a constituent of some essential oils, mainly oil of guaiac and 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. Applications Guaiazulene is an 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 Allantoin is a chemical compound with formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide. It is a diureide of glyoxylic acid. Allantoin is a major metabolic intermediate in most organisms ... [...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 (Help:IPA/English, /ɪˈnænti.əmə ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caryophyllene
Caryophyllene (), more formally (−)-β-caryophyllene (BCP), is a natural bicyclic sesquiterpene that occurs widely in nature. Caryophyllene is notable for having a cyclobutane ring, as well as a ''trans''-double bond in a 9-membered ring, both rarities in nature. Production Caryophyllene can be produced synthetically, but it is invariably obtained from natural sources because it is widespread. It 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'', copaiba, rosemary, and hops. It is usually found as a mixture with isocaryophyllene (the ''cis'' double bond isomer) and humulene, α-humulene (obsolete name: α-caryophyllene), a ring-opened isomer. Caryophyllene is one of the chemical compounds that contributes to the odor, aroma of black pepper. Basic research β-Caryophyllene is under basic research for its potential action as an agonist of the cannab ... [...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, whil ... [...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 (Help:IPA/English, /ɪˈnænti.əmə ... [...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, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
