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Cembrene A
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 is 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. ''Pinus leucodermis'' tree bark and wood essential oils contain a high percentage of cembrene. Cembrenes are biosynthesized by macrocyclization of 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, whic .... 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 ≥ 2. Terpenes are major biosynthetic building blocks. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly Pinophyta, conifers. In plants, terpenes and terpenoids are important mediators of ecological biological interaction, interactions, while some insects use some terpenes as a form of defense. Other functions of terpenoids include cell growth modulation and plant elongation, light harvesting and photoprotection, and membrane permeability and fluidity control. Terpenes are 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. The one terpene that has major applications is natural rubber (i.e., polyisoprene). The possibility that other terpenes could be used as precursors to pr ... [...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 A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ... 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'' (Versevel ... [...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 language, Greek () and (). Pheromones are also sometimes classified as ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Leucodermis
''Pinus heldreichii'', the Bosnian pine or Heldreich's pine, is a species of pine native to mountains of southeast Europe in the Balkans and southern Italy. Description It is an evergreen tree up to in height, and in trunk diameter. The bark is smooth pale grey at first, becoming hard and tesselated into small hexagonal to rounded plates (somewhat reminiscent of crocodile skin) in old trees. It is a member of the hard pine group, ''Pinus'' subgenus ''Pinus'', with leaves ('needles') in fascicles (bundles) of two, with a persistent sheath. They are long and thick. Cones are long, with thin, fragile scales; they are dark blue-purple before maturation, turning brown when ripe about 16–18 months after pollination. The long seeds have a wing and are wind- dispersed. File:Байкушева мура 01.JPG, Trunk of an old tree ('Baikushev's pine') File:Pinus heldreichii leg P.Cikovac Jastrebica Mt Orjen.jpg, Bark on an old tree, showing the distinctive "crocodile-skin" pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is essential in the sense that it contains the essence of the plant's fragrance—the characteristic fragrance of the plant from which it is derived. The term "essential" used here does ''not'' mean required or usable by the human body, as with the terms essential amino acid or essential fatty acid, which are so called because they are nutritionally required by a living organism. Essential oils are generally extracted by distillation, often by using steam. Other processes include expression, solvent extraction, '' sfumatura'', absolute oil extraction, resin tapping, wax embedding, and cold pressing. They are used in perfumes, cosmetics, soaps, ... [...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 macrocyclization. The central challenge to macrocyclization is that ring-closing reactions do not favor the formation of large rings. Instead, medium sized rings or polymers tend to form. Early macrocyclizations were achieved ketonic decarboxylations for the preparation of terpenoid macrocycles. So, while Ružička was able to produce various macrocycles, the yields were low. This kinetic problem can be addressed by using high-dilution reactions, whereby intramolecular processes are favored relative to polymerizations. Reactions amenable to high dilution include Dieckmann condensation and related based-induced reactions of esters with remote halides. Some macrocyc ... [...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 Geranylgeraniol is a diterpenoid alcohol. It is a colorless waxy solid. It is an important intermediate in the biosynthesis of other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpenes
Diterpenes are a class of terpenes 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. Some diterpenes are known to be antimicrobial and anti-inflammatory. 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 geran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkene Derivatives
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as α-olefins. 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 ''n'' being a >1 natural number (which is two hydrogens less than the corresponding alkane). When ''n'' is four or more, isomers are possible, distinguished by the position and conformation of the double bond. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Ecology
Insect ecology is the interaction of insects, individually or as a community, with the surrounding Natural environment, environment or ecosystem. This interaction is mostly mediated by the secretion and detection of chemicals (semiochemical) in the environment by insects. Semiochemicals are secreted by the organisms (including insects) in the environment and they are detected by other organism such as insects. Semiochemicals used by organisms, including (insects) to interact with other organism either of the same species or different species can generally grouped into four. These are pheromone, synomones, allomone and kairomone. Pheromones are semiochemicals that facilitates interaction between organisms of same species. Synomones benefit both the producer and receiver, allomone is advantageous to only the producer whiles kairomones is beneficial to the receiver. Insect interact with other species within their community and these interaction include Mutualism (biology), mutua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Pheromones
Insect pheromones are neurotransmitters that serve the chemical communication between individuals of an insect species. They thus differ from kairomones, in other words, neurotransmitters that transmit information to non-species organisms. Insects produce pheromones in special glands and release them into the environment. In the pheromone receptors of the sensory cells of the recipient, they produce a nerve Stimulus (physiology), stimulus even in very low concentrations, which ultimately leads to a behavioral response. Biological specificity, Intraspecific communication of insects via these substances takes place in a variety of ways and serves, among other things, to find sexual partner, to maintain harmony in a Colony (biology), colony of Eusociality, socially living insects, to mark territories or to find nest sites and food sources. In 1959, the German biochemist and Nobel Prize winner Adolf Butenandt identified and synthesized the Saturated and unsaturated compounds, unsatura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
