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Monoterpene
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 precu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halomon
Halomon is a polyhalogenated monoterpene first isolated from the marine red algae '' Portieria hornemannii''. Halomon has attracted research interest because of its promising profile of selective cytotoxicity that suggests its potential use as an antitumor agent. Halomon is in a class of chemical compounds known as halocarbons, which are often potent alkylating agents which may be toxic to individual cells or to living organisms. The red algae that naturally produce halomon and other related compounds probably do so as a poisonous defense against fish or other marine life that may see it as a potential source of food. Halomon, however, is a selective toxin; studies at the National Cancer Institute have indicated that it is more toxic to certain types of tumor cells than to other cells. The algae that produces halomon is difficult to locate, identify, and collect and the concentration of halomon in the organism is extremely low. Therefore, obtaining a sufficient amount of ... [...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 some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linalool
Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of spiciness). A colorless oil, linalool is classified as an acyclic monoterpenoid. In plants, it is a metabolite, a volatile oil component, an antimicrobial agent, and an aroma compound. Linalool has uses in manufacturing of soaps, fragrances, food additives as flavors, household products, and insecticides. Esters of linalool are referred to as linalyl, e.g. linalyl pyrophosphate, an isomer of geranyl pyrophosphate. The word ''linalool'' is based on ''linaloe'' (a type of wood) and the suffix '. In food manufacturing, it may be called ''coriandrol''. Occurrence Both enantiomeric forms are found in nature: (''S'')-linalool is found, for example, as a major constituent of the essential oils of coriander ('' Coriandrum sativum'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camphene
Camphene is a bicyclic organic compound. It is one of the most pervasive monoterpenes. As for other terpenes, it is insoluble in water, flammable, colorless, and has a pungent smell. It is a minor constituent of many essential oils such as turpentine, cypress oil, camphor oil, citronella oil, neroli, ginger oil, valerian, and mango. It is produced industrially by isomerization of the more common alpha-pinene using a solid acid catalyst such as titanium dioxide. Camphene is used in the preparation of fragrances and as a food additive for flavoring. These include isobornyl acetate. Biosynthesis Camphene is biosynthesized from linalyl pyrophosphate via a sequence of carbocation A carbocation is an ion with a positively charged carbon atom. Among the simplest examples are the methenium , methanium and vinyl cations. Occasionally, carbocations that bear more than one positively charged carbon atom are also encounte ...ic intermediates. References {{Author ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sabinene
Sabinene is a natural bicyclic monoterpene with the molecular formula C10H16. It is isolated from the essential oils of a variety of plants including Marjoram, holm oak (''Quercus ilex'') and Norway spruce (''Picea abies''). It has a strained ring system with a cyclopentane ring fused to a cyclopropane ring. Sabinene is one of the chemical compounds that contributes to the spiciness of black pepper and is a major constituent of carrot seed oil. It also occurs in tea tree oil at a low concentration. It is also present in the essential oil obtained from nutmeg, '' Laurus nobilis'', and '' Clausena anisata''. Biosynthesis Sabinene, a bicyclic monoterpene, is present in the (+) and (-) enantiomers. It is biosynthesized from the common terpenoid precursor, geranyl pyrophosphate (GPP) that undergoes polycyclization catalyzed by sabinene synthase (SabS). GPP is formed from the terpenoid synthesis pathway with the starter units, isopentenyl pyrophosphate Isopentenyl pyrophospha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linalool
Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of spiciness). A colorless oil, linalool is classified as an acyclic monoterpenoid. In plants, it is a metabolite, a volatile oil component, an antimicrobial agent, and an aroma compound. Linalool has uses in manufacturing of soaps, fragrances, food additives as flavors, household products, and insecticides. Esters of linalool are referred to as linalyl, e.g. linalyl pyrophosphate, an isomer of geranyl pyrophosphate. The word ''linalool'' is based on ''linaloe'' (a type of wood) and the suffix '. In food manufacturing, it may be called ''coriandrol''. Occurrence Both enantiomeric forms are found in nature: (''S'')-linalool is found, for example, as a major constituent of the essential oils of coriander ('' Coriandrum sativum'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hinokitiol
Hinokitiol (β-thujaplicin) is a natural monoterpenoid found in the wood of trees in the family Cupressaceae. It is a tropolone derivative and one of the thujaplicins. Hinokitiol is used in oral and skin care products, and is a food additive used in Japan. History Hinokitiol was discovered by a Japanese chemist Tetsuo Nozoe in 1936. It was isolated from the essential oil component of the heartwood of '' Taiwanese hinoki'', from which the compound ultimately adopted its name. Hinokitiol is the first non- benzenoid aromatic compound identified. The compound has a heptagonal molecular structure and was first synthesyzed by Ralph Raphael in 1951. Due to its iron-chelating activity, hinokitiol has been called an "Iron Man molecule" in the scientific media, which is ironic because Tetsuo is translated into English as "Iron Man". Taiwanese hinoki is native to East Asian countries, particularly to Japan and Taiwan. Hinokitiol has also been found in other trees of the ''Cupressaceae' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limonene
Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels. The -isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring agent in food manufacturing. It is also used in chemical synthesis as a precursor to carvone and as a renewables-based solvent in cleaning products. The less common -isomer has a piny, turpentine-like odor, and is found in the edible parts of such plants as caraway, dill, and bergamot orange plants. Limonene takes its name from Italian ''limone'' ("lemon"). Limonene is a chiral molecule, and biological sources produce one enantiomer: the principal industrial source, citrus fruit, contains -limonene ((+)-limonene), which is the (''R'')-enantiomer. Racemic limonene is known as dipentene. -Limonene is obtained commercially from citrus fruits through two primary methods: centrifugal separation or steam distillation. Chemical reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menthol
Menthol is an organic compound, more specifically a monoterpenoid, made synthetically or obtained from the oils of corn mint, peppermint, or other mints. It is a waxy, clear or white crystalline substance, which is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is (−)-menthol, which is assigned the (1''R'',2''S'',5''R'') configuration. Menthol has local anesthetic and counterirritant qualities, and it is widely used to relieve minor throat irritation. Menthol also acts as a weak κ-opioid receptor agonist. Structure Natural menthol exists as one pure stereoisomer, nearly always the (1''R'',2''S'',5''R'') form (bottom left corner of the diagram below). The eight possible stereoisomers are: : In the natural compound, the isopropyl group is in the '' trans'' orientation to both the methyl and hydroxyl groups. Thus, it can be drawn in any of the ways shown: : The (+)- and (−)- enantiomers of menthol are the most stab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eucalyptol
Eucalyptol is a monoterpenoid. A colorless liquid, it is a bicyclic ether. Eucalyptol has a fresh mint-like smell and a spicy, cooling taste. It is insoluble in water, but miscible with organic solvents. Eucalyptol makes up ~70% - 90% of eucalyptus oil. Eucalyptol forms crystalline adducts with hydrohalic acids, ''o''-cresol, resorcinol, and phosphoric acid. Formation of these adducts is useful for purification. In 1870, F. S. Cloez identified and ascribed the name "eucalyptol" to the dominant portion of '' Eucalyptus globulus'' oil. Uses Because of its pleasant, spicy aroma and taste, eucalyptol is used in flavorings, fragrances, and cosmetics. Cineole-based eucalyptus oil is used as a flavouring at low levels (0.002%) in various products, including baked goods, confectionery, meat products, and beverages. In a 1994 report released by five top cigarette companies, eucalyptol was listed as one of the 599 additives to cigarettes. It is claimed to be added to improve the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citral
Citral is an acyclic monoterpene aldehyde, and being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the ''E''-isomer is named geranial (''trans''-citral) or citral A. The ''Z''-isomer is named neral (''cis''-citral) or citral B. These stereoisomers occur as a mixture, not necessarily racemic; e.g. in essential oil of Australian ginger, the neral to geranial ratio is 0.61. Occurrence Citral is present in the oils of several plants, including lemon myrtle (90–98%), '' Litsea citrata'' (90%), '' Litsea cubeba'' (70–85%), lemongrass (65–85%), lemon tea-tree (70–80%), ''Ocimum gratissimum'' (66.5%), '' Lindera citriodora'' (about 65%), '' Calypranthes parriculata'' (about 62%), petitgrain (36%), lemon verbena (30–35%), lemon ironbark (26%), lemon balm (11%), lime (6–9%), lemon (2–5%), and orange. Further, in the lipid fraction (essential oil) of Australian ginger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocimene
Ocimenes are a group of isomeric hydrocarbons. The ocimenes are monoterpenes found within a variety of plants and fruits. α-Ocimene and the two β-ocimenes differ in the position of the isolated double bond: it is terminal in the alpha isomer. α-Ocimene is ''cis-''3,7-dimethyl-1,3,7-octatriene. β-Ocimene is ''trans-''3,7-dimethyl-1,3,6-octatriene. β-Ocimene exists in two stereoisomeric forms, ''cis'' and ''trans,'' with respect to the central double bond. The ocimenes are often found naturally as mixtures of the various forms. The mixture, as well as the pure compounds, are oils with a pleasant odor. They are used in perfumery for their sweet herbal scent, and are believed to act as plant defense and have anti-fungal properties. Like the related acyclic terpene myrcene, ocimenes are unstable in air.Karl-Georg Fahlbusch, Franz-Josef Hammerschmidt, Johannes Panten, Wilhelm Pickenhagen, Dietmar Schatkowski, Kurt Bauer, Dorothea Garbe, Horst Surburg "Flavors and Fragrances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
