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Hopane
Hopane is a natural chemical compound classified as a triterpene. It forms the central core of a variety of other chemical compounds which are collectively known as hopanoids. The first compound of the hopane family to be isolated and characterised was hydroxyhopanone, found in dammar resin. The name derives from ''Hopea ''Hopea'' is a genus of plants in the family Dipterocarpaceae. The genus was named after John Hope, 1725–1786, the first Regius Keeper of the Royal Botanic Garden, Edinburgh. It contains some 113 species, distributed from Sri Lanka and south ...'', a tree genus from which dammar is obtained. See also * Bacteriohopanepolyol References Triterpenes Hydrocarbons Cyclopentanes Isopropyl compounds {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triterpene
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids. Structures Triterpenes exist in a great variety of structures. Nearly 200 different skeletons have been identified. These skeletons may be broadly divided according to the number of rings present. In general pentacyclic structures (5 rings) tend to dominate. Squalene is biosynthesized through the head-to-head condensation of two farnesyl pyrophosphate units. This coupling converts a pair of C15 components into a C30 product. Squalene serves as precursor for the formation of many triterpenoids, including bacterial hopanoids and eukaryotic sterols. Triterpenoids By definition triterpenoids are triterpenes that possess heteroatoms, usually oxygen. The terms ''triterpene'' and ''triterpenoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triterpenes
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids. Structures Triterpenes exist in a great variety of structures. Nearly 200 different skeletons have been identified. These skeletons may be broadly divided according to the number of rings present. In general pentacyclic structures (5 rings) tend to dominate. Squalene is biosynthesized through the head-to-head condensation of two farnesyl pyrophosphate units. This coupling converts a pair of C15 components into a C30 product. Squalene serves as precursor for the formation of many triterpenoids, including bacterial hopanoids and eukaryotic sterols. Triterpenoids By definition triterpenoids are triterpenes that possess heteroatoms, usually oxygen. The terms ''triterpene'' and ''triterpenoid'' o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hopanoid
Hopanoids are a diverse subclass of triterpenoids with the same hydrocarbon skeleton as the compound hopane. This group of pentacyclic molecules therefore refers to simple hopenes, hopanols and hopanes, but also to extensively functionalized derivatives such as bacteriohopanepolyols (BHPs) and hopanoids covalently attached to lipid A. The first known hopanoid, hydroxyhopanone, was isolated by two chemists at The National Gallery, London working on the chemistry of dammar gum, a natural resin used as a varnish for paintings. While hopanoids are often assumed to be made only in bacteria, their name actually comes from the abundance of hopanoid compounds in the resin of plants from the genus ''Hopea''. In turn, this genus is named after John Hope, the first Regius Keeper of the Royal Botanic Garden, Edinburgh. Since their initial discovery in an angiosperm, hopanoids have been found in plasma membranes of bacteria, lichens, bryophytes, ferns, tropical trees and fungi. Hopanoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriohopanepolyol
Bacteriohopanepolyols (BHPs), bacteriohopanoids, or bacterial pentacyclic triterpenoids are commonly found in the lipid cell membranes of many bacteria. BHPs are frequently used as biomarkers in sedimentary rocks and can provide paleoecological information about ancient bacterial communities. See also *Hopane Hopane is a natural chemical compound classified as a triterpene. It forms the central core of a variety of other chemical compounds which are collectively known as hopanoids. The first compound of the hopane family to be isolated and character ... References {{Reflist Terpenes and terpenoids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union Of Pure And Applied Chemistry
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is a member of the International Science Council (ISC). IUPAC is registered in Zürich, Switzerland, and the administrative office, known as the "IUPAC Secretariat", is in Research Triangle Park, North Carolina, United States. This administrative office is headed by IUPAC's executive director, currently Lynn Soby. IUPAC was established in 1919 as the successor of the International Congress of Applied Chemistry for the advancement of chemistry. Its members, the National Adhering Organizations, can be national chemistry societies, national academies of sciences, or other bodies representing chemists. There are fifty-four National Adhering Organizations and three Associate National Adhering Organizations. IUPAC's Inter-divisional Committee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, China and in Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dammar
Dammar, also called dammar gum, or damar gum, is a resin obtained from the tree family Dipterocarpaceae in India and Southeast Asia, principally those of the genera '' Shorea'' or '' Hopea'' (synonym ''Balanocarpus''). The resin of some species of ''Canarium'' may also called dammar. Most is produced by tapping trees; however, some is collected in fossilised form on the ground. The gum varies in colour from clear to pale yellow, while the fossilised form is grey-brown. Dammar gum is a triterpenoid resin, containing many triterpenes and their oxidation products. Many of them are low molecular weight compounds (dammarane, dammarenolic acid, oleanane, oleanonic acid, etc.), but dammar also contains a polymeric fraction, composed of polycadinene. The name ''dammar'' is a Malay word meaning ‘resin’ or ‘torch made from resin’. Types * ''Damar mata kucing'' (‘cat's eye damar’) is a crystalline resin, usually in the form of round balls. ''Shorea javanica'' is an impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hopea
''Hopea'' is a genus of plants in the family Dipterocarpaceae. The genus was named after John Hope, 1725–1786, the first Regius Keeper of the Royal Botanic Garden, Edinburgh. It contains some 113 species, distributed from Sri Lanka and southern India to southern China, and southward throughout Malesia to New Guinea. They are mainly main and subcanopy trees of lowland rainforest, but some species can become also emergent trees, such as '' Hopea nutans''. Species accepted: Other species recently used, but now not accepted include: *'' Hopea exalata'', now a synonym of '' Hopea reticulata'' *''Hopea kitulgallensis'', not now accepted *''Hopea malabarica'', now a synonym of '' Hopea racophloea'' *'' Hopea quisumbingiana'', not now accepted *'' Hopea siamensis'', now a synonym of ''Hopea pierrei'' *'' Hopea wightiana'' Wall., now a synonym of ''Hopea ponga'' Gallery File:Hopea beccariana Base du tronc.JPG, ''Hopea beccariana'' File:A leaf of Hopea odorata.jpg, ''Hopea odorat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocarbons
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 ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentanes
Cyclopentane (also called C pentane) is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It occurs as a colorless liquid with a petrol-like odor. Its melting point is −94 °C and its boiling point is 49 °C. Cyclopentane is in the class of cycloalkanes, being alkanes that have one or more rings of carbon atoms. It is formed by cracking cyclohexane in the presence of alumina at a high temperature and pressure. It was first prepared in 1893 by the German chemist Johannes Wislicenus. Production, occurrence and use Cycloalkanes are formed by catalytic reforming. For example, when passed over a hot platinum surfact, 2-methylbutane converts into cyclopentane. Cyclopentane has no particular use. No commercial products are made from cyclopentane itself. As a volatile hydrocarbon it is an incidental component of some fuels and b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
