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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] |
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] |
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 Fragranc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carvone
Carvone is a member of a family of chemicals called terpenoids. Carvone is found naturally in many essential oils, but is most abundant in the oils from seeds of caraway (''Carum carvi''), spearmint (''Mentha spicata''), and dill. Uses Both carvones are used in the food and flavor industry. ''R''-(−)-Carvone is also used for air freshening products and, like many essential oils, oils containing carvones are used in aromatherapy and alternative medicine. ''S''-(+)-Carvone has shown a suppressant effect against high-fat diet induced weight gain in mice. Food applications As the compound most responsible for the flavor of caraway, dill and spearmint, carvone has been used for millennia in food. Wrigley's Spearmint Gum and spearmint flavored Life Savers are major users of natural spearmint oil from '' Mentha spicata''. Caraway seed is extracted with alcohol to make the European drink Kümmel. Agriculture ''S''-(+)-Carvone is also used to prevent premature sprouting of potato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or exemplified by the odors of gasoline and lighter fluid. They occur in a diverse range of molecular structures and phases: they can be gases (such as methane and propane), liquids (such as hexane and benzene), low melting solids (such as paraffin wax and naphthalene) or polymers (such as polyethylene and polystyrene). In the fossil fuel industries, ''hydrocarbon'' refers to the naturally occurring petroleum, natural gas and coal, and to their hydrocarbon derivatives and purified forms. Combustion of hydrocarbons is the main source of the world's energy. Petroleum is the dominant raw-material source for organic commodity chemicals such as solvents and polymers. Most anthropogenic (human-generated) emissions of greenhouse gases are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myrcene
Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from ''Myrcia'', from which it gets its name. It is an intermediate in the production of several fragrances. α-Myrcene is the name for the isomer 2-methyl-6-methylene-1,7-octadiene, which has not been found in nature. Production Myrcene is often produced commercially by the pyrolysis (400 °C) of β-pinene, which is obtained from turpentine. It is rarely obtained directly from plants. Plants biosynthesize myrcene via geranyl pyrophosphate (GPP), which isomerizes into linalyl pyrophosphate. The release of the pyrophosphate (OPP) and a proton completes the conversion. Occurrence It could in principle be extracted from any number of plants, such as verbena or wild thyme, the leaves of which contain up to 40% by weight of myrcene. Many other plants contain myrcene, sometimes in substantial amounts. Some of these include cannabis, hops, ''Hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myrcene
Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from ''Myrcia'', from which it gets its name. It is an intermediate in the production of several fragrances. α-Myrcene is the name for the isomer 2-methyl-6-methylene-1,7-octadiene, which has not been found in nature. Production Myrcene is often produced commercially by the pyrolysis (400 °C) of β-pinene, which is obtained from turpentine. It is rarely obtained directly from plants. Plants biosynthesize myrcene via geranyl pyrophosphate (GPP), which isomerizes into linalyl pyrophosphate. The release of the pyrophosphate (OPP) and a proton completes the conversion. Occurrence It could in principle be extracted from any number of plants, such as verbena or wild thyme, the leaves of which contain up to 40% by weight of myrcene. Many other plants contain myrcene, sometimes in substantial amounts. Some of these include cannabis, hops, ''Hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentose
In chemistry, a pentose is a monosaccharide (simple sugar) with five carbon atoms. The chemical formula of many pentoses is , and their molecular weight is 150.13 g/mol.-Ribose . PubChem compound webpage, accessed on 2010-02-06. Pentoses are very important in . is a constituent of , and the related molecule, , is a constituent of [...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 reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borneol
Borneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an '' endo'' position. The exo diastereomer is called isoborneol. Being chiral, borneol exists as enantiomers, both of which are found in nature. Reactions Borneol is oxidized to the ketone (camphor). Occurrence The compound was named in 1842 by the French chemist Charles Frédéric Gerhardt. Borneol can be found in several species of ''Heterotheca'', '' Artemisia'', ''Rosmarinus officinalis'' (rosemary) '' Dipterocarpaceae'', '' Blumea balsamifera'' and '' Kaempferia galanga''. It is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's plant food. Synthesis Borneol can be synthesized by reduction of camphor by the Meerwein–Ponndorf–Verley reduction (a reversible process). Reduction of camphor with sodium borohydride (fast and irreversible) gives instead the diastereomer isoborneol. : Uses Whereas ''d''-borneo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camphor
Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel ('' Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the kapur tree ( ''Dryobalanops'' sp.), a tall timber tree from South East Asia. It also occurs in some other related trees in the laurel family, notably '' Ocotea usambarensis''. Rosemary leaves ('' Rosmarinus officinalis'') contain 0.05 to 0.5% camphor, while camphorweed ('' Heterotheca'') contains some 5%. A major source of camphor in Asia is camphor basil (the parent of African blue basil). Camphor can also be synthetically produced from oil of turpentine. The compound is chiral, existing in two possible enantiomers as shown in the structural diagrams. The structure on the left is the naturally occurring (+)-camphor ((1''R'',4''R'')-bornan-2-one), while its mirror image shown on the right is the (−)-camphor ((1''S'',4''S'')-bornan-2-o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thujene
Thujene (or α-thujene) is a natural organic compound classified as a monoterpene. It is found in the essential oils of a variety of plants, and contributes pungency to the flavor of some herbs such as Summer savory.''PDR for Herbal Medicines'', Third Edition, Joerg Gruenwald (Editor), page 802. The term ''thujene'' usually refers to α-thujene. A less common chemically related double-bond 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. Iso ... is known as β-thujene (or 2-thujene). Another double-bond isomer is known as sabinene. {, class="toccolours" border="1" style="margin: 0 0 1em 1em; border-collapse: collapse;" , colspan="3" align="center" , Chemical structure comparison , - , , , , - , align="center", α-Thujene , align="center", β-Thujene , align="cent ... [...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 encoun ...ic intermediates. References {{Authority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
