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Neo-cembrene
Cembrene A, or sometimes neocembrene, is a natural monocyclic diterpene isolated from corals of the genus '' Nephthea''. It is a colorless oil with a faint wax-like odor. Cembrene A itself has little importance as a chemical entity, being a trail pheromone for termites; however, the chemical structure of cembrene is central to a very wide variety of other natural products found both in plants and in animals.''Terpenes: Flavors, Fragrances, Pharmaca, Pheromones'', Eberhard Breitmaier, page 7. Cembrenes are biosynthesized by macrocyclization Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry. ... of geranylgeranyl pyrophosphate. References {{reflist Diterpenes Alkene derivatives Insect ecology Insect pheromones Cycloalkenes ... [...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] |
Nephthea
''Litophyton'' is a genus of soft corals in the family Nephtheidae. Species The World Register of Marine Species includes the following species in the genus: *''Litophyton acuticonicum'' (Verseveldt, 1974) *'' Litophyton amentaceum'' (Studer, 1894) *'' Litophyton arboreum'' Forskål, 1775 *''Litophyton bayeri'' (Verseveldt, 1966) *'' Litophyton berdfordi'' (Shann, 1912) *''Litophyton brassicum'' (Kükenthal, 1903) *'' Litophyton bumastum'' (Verseveldt, 1973) *'' Litophyton capnelliformis'' (Thomson & Dean, 1931) *'' Litophyton carnosum'' (Kükenthal) *''Litophyton cervispiculosum'' (Thomson & Dean, 1931) *'' Litophyton chabrolii'' (Andouin, 1828) *''Litophyton columnaris'' (Studer, 1895) *'' Litophyton compactum'' (Verseveldt, 1966) *''Litophyton concinnum'' (Kükenthal, 1905) *'' Litophyton corallinum'' (Kükenthal, 1910) *''Litophyton crassum'' (Kükenthal, 1903) *''Litophyton cupressiformis'' (Kükenthal, 1903) *''Litophyton curvum'' van Ofwegen, 2016 *''Litophyton debilis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are ''alarm signal, alarm pheromones'', ''food trail pheromones'', ''sex pheromones'', and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology. Background The portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω ''pheroo'' ('I carry') and ὁρμων ''hormon'' ('stimulating'). P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrocycle
Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry. Synthesis The formation of macrocycles by ring-closure is called macrocylization. Pioneering work was reported for studies on terpenoid macrocycles. The central challenge to macrocyclization is that ring-closing reactions do not favor the formation of large rings. Instead, small rings or polymers tend to form. This kinetic problem can be addressed by using high-dilution reactions, whereby intramolecular processes are favored relative to polymerizations. Some macrocyclizations are favored using template reactions. Templates are ions, molecules, surfaces etc. that bind and pre-organize compounds, guiding them toward formation of a particular ring size. The crown ethers are often generated in the presence of an alkali metal cation, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geranylgeranyl Pyrophosphate
Geranylgeranyl pyrophosphate is an intermediate in the biosynthesis of diterpenes and diterpenoids. It is also the precursor to carotenoids, gibberellins, tocopherols, and chlorophylls. It is also a precursor to geranylgeranylated proteins, which is its primary use in human cells. It is formed from farnesyl pyrophosphate by the addition of an isoprene unit from isopentenyl pyrophosphate. In ''Drosophila'', geranylgeranyl pyrophosphate is synthesised by HMG-CoA encoded by the Columbus gene. Geranylgeranyl pyrophosphate is utilised as a chemoattractant for migrating germ cells that have traversed the midgut epithelia. The attractant signal is produced at the gonadal precursors, directing the germ cells to these sites, where they will differentiate into eggs and spermatozoa (sperm). Related compounds * Farnesyl pyrophosphate * Geranylgeraniol * Geranyl pyrophosphate Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), is the pyrophosphate ester of the terpenoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpenes
Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being a primary intermediate. Diterpenes form the basis for biologically important compounds such as retinol, retinal, and phytol. They are known to be antimicrobial and antiinflammatory. Structures As with most terpenes a huge number of potential structures exists, which may be broadly divided according to the number of rings present. Biosynthesis Diterpenes are derived from the addition of one IPP unit to FPP to form geranylgeranyl-pyrophosphate (GGPP). From GGPP, structural diversity is achieved mainly by two classes of enzymes; the diterpene synthases and cytochromes P450. Several diterpenes are produced by plants and cyanobacteria. GGPP is also the precursor for the synthesis of the phytane by the action of the enzyme geranylger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkene Derivatives
In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, and Biological Chemistry'. 1232 pages. Two general types of monoalkenes are distinguished: terminal and internal. Also called α-olefins, terminal alkenes are more useful. However, the International Union of Pure and Applied Chemistry (IUPAC) recommends using the name "alkene" only for acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc. for cyclic ones; and "olefin" for the general class – cyclic or acyclic, with one or more double bonds. Acyclic alkenes, with only one double bond and no other functional groups (also known as mono-enes) form a homologous series of hydrocarbons with the general formula with '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Ecology
Insect ecology is the scientific study of how insects, individually or as a community, interact with the surrounding environment or ecosystem. Insects play significant roles in the ecology of the world due to their vast diversity of form, function and lifestyle; their considerable biomass; and their interaction with plant life, other organisms and the environment. Since they are the major contributor to biodiversity in the majority of habitats, except in the sea, they accordingly play a variety of extremely important ecological roles in the many functions of an ecosystem. Taking the case of nutrient recycling, insects contribute to this vital function by degrading or consuming leaf litter, wood, carrion and dung and by dispersal of fungi. Insects form an important part of the food chain, especially for entomophagous vertebrates such as many mammals, birds, amphibians and reptiles. Insects play an important role in maintaining community structure and composition; in the case of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Pheromones
Insects (from Latin ') are pancrustacean Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, Thorax (insect anatomy), thorax and abdomen (insect anatomy), abdomen), three pairs of jointed Arthropod leg, legs, compound eyes and one pair of antenna (biology), antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of Extant taxon, extant species is estimated at between six and ten million; In: potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all Natural environment, environments, although only a small number of species reside in the oceans, which are dominated by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
