Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids.[1] A recent study conducted in the Cosmics Leaving Outdoor Droplets large cloud chamber at CERN, has identified sesquiterpenes — gaseous hydrocarbons that are released by plants — as potentially playing a major role in cloud formation in relatively pristine regions of the atmosphere.[2]
Cyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors. In addition to common six-membered ring systems such as the ones found in zingiberene and bisacurone, cyclization of one end of the chain to the other end can lead to macrocyclic rings such as humulene.
Zingiberene, a sesquiterpene abundant in ginger.δ-Cadinene, one of a family of sesquiterpene.Humulones are sesquiterpenoids that give "hoppy" flavor to beer.
The cadinenes contain two fused six-membered rings. Caryophyllene, a component of many essential oils such as clove oil, contains a nine-membered ring fused to a cyclobutane ring. Rishitin is another example of a cadinene, which is found in potatoes and tomatoes.[5][6]
With the addition of a third ring, the possible structures become increasingly varied. Examples include longifolene, copaene and the alcohol patchoulol.
SesquiterpenoidsEdit
The FPP backbone can be rearranged in several different ways and further decorated with different functional groups, hence the large variety of sesquiterpenoids. Geosmin, the volatile compound that gives an earthy taste and musty odor in drinking water and the characteristic odor on a rainy day, is a sesquiterpenoid, produced by bacteria, especially cyanobacteria, that are present in the soils and water supplies.[7] Oxidation of farnesene then provides the sesquiterpenoid farnesol.
Sesquiterpene lactones are a common class of sesquiterpenoids that contain a lactone ring, hence the name. They are found in many plants and can cause allergic reactions and toxicity if consumed excessively, particularly in grazing livestock.[8]
The term merosesquiterpenoids was coined in 1968 to describe molecules of this class that have a mixed biosynthetic origin, meaning isoprenoid precursors like isopentenyl pyrophosphate are derived from both the mevalonate and non-mevalonate pathways.[9]
^Davis, Edward M.; Croteau, Rodney (2000). "Cyclization Enzymes in the Biosynthesis of Monoterpenes, Sesquiterpenes, and Diterpenes". Topics in Current Chemistry. 209: 53–95. doi:10.1007/3-540-48146-X_2. ISBN978-3-540-66573-1.
^Chizzola R (2013), "Regular Monoterpenes and Sesquiterpenes (Essential Oils)", Natural Products, Springer Berlin Heidelberg, pp. 2973–3008, doi:10.1007/978-3-642-22144-6_130, ISBN9783642221439
^Katsui, N., Murai, A., Takasugi, M., Imaizumi, K., Masamune, T., & Tomiyama, K. (1968). The structure of rishitin, a new antifungal compound from diseased potato tubers. Chemical Communications, (1), 43. https://doi.org/10.1039/c19680000043
^D’Harlingue, A., Mamdouh, A. M., Malfatti, P., Soulie, M.-C., & Bompeix, G. (1995). Evidence for rishitin biosynthesis in tomato cultures. Phytochemistry, 39(1), 69–70. https://doi.org/10.1016/0031-9422(94)00844-J
^Izaguirre G, Taylor WD (June 1995). "Geosmin and 2-methylisoborneol production in a major aqueduct system". Water Science and Technology. 31 (11): 41–48. doi:10.1016/0273-1223(95)00454-u.
^"Sesquiterpene Lactones and their toxicity to livestock". Cornell CALS. Cornell University. Retrieved December 29, 2018.
^Simpson, Thomas J.; Ahmed, Salman A.; Rupert McIntyre, C.; Scott, Fiona E.; Sadler, Ian H. (1997-03-17). "Biosynthesis of polyketide-terpenoid (meroterpenoid) metabolites andibenin B and andilesin A in Aspergillus variecolor". Tetrahedron. 53 (11): 4013–4034. doi:10.1016/S0040-4020(97)00015-X. ISSN 0040-4020.
External linksEdit
Look up sesquiterpene in Wiktionary, the free dictionary.
sesquiterpene, class, terpenes, that, consist, three, isoprene, units, often, have, molecular, formula, c15h24, like, monoterpenes, sesquiterpenes, cyclic, contain, rings, including, many, unique, combinations, biochemical, modifications, such, oxidation, rear. Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24 Like monoterpenes sesquiterpenes may be cyclic or contain rings including many unique combinations Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids 1 A recent study conducted in the Cosmics Leaving Outdoor Droplets large cloud chamber at CERN has identified sesquiterpenes gaseous hydrocarbons that are released by plants as potentially playing a major role in cloud formation in relatively pristine regions of the atmosphere 2 Big Sagebrush Artemisia tridentata contains sesquiterpene lactones which are sesquiterpenoids built from three isoprene units and contain a lactone ring hence the name These compounds are found in many other plants and can cause allergic reactions and toxicity if consumed in excess particularly in grazing livestock Phallus indusiatus in Cooktown Queensland Australia which produces two unique sesquiterpenes Contents 1 Biosynthesis and examples 1 1 Sesquiterpenoids 2 References 3 External linksBiosynthesis and examples EditThe reaction of geranyl pyrophosphate with isopentenyl pyrophosphate results in the 15 carbon farnesyl pyrophosphate FPP which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene 3 4 nbsp Farnesyl pyrophosphateCyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors In addition to common six membered ring systems such as the ones found in zingiberene and bisacurone cyclization of one end of the chain to the other end can lead to macrocyclic rings such as humulene nbsp Zingiberene a sesquiterpene abundant in ginger nbsp d Cadinene one of a family of sesquiterpene nbsp Humulones are sesquiterpenoids that give hoppy flavor to beer The cadinenes contain two fused six membered rings Caryophyllene a component of many essential oils such as clove oil contains a nine membered ring fused to a cyclobutane ring Rishitin is another example of a cadinene which is found in potatoes and tomatoes 5 6 Vetivazulene and guaiazulene are aromatic bicyclic sesquiterpenoids With the addition of a third ring the possible structures become increasingly varied Examples include longifolene copaene and the alcohol patchoulol Sesquiterpenoids Edit The FPP backbone can be rearranged in several different ways and further decorated with different functional groups hence the large variety of sesquiterpenoids Geosmin the volatile compound that gives an earthy taste and musty odor in drinking water and the characteristic odor on a rainy day is a sesquiterpenoid produced by bacteria especially cyanobacteria that are present in the soils and water supplies 7 Oxidation of farnesene then provides the sesquiterpenoid farnesol Sesquiterpene lactones are a common class of sesquiterpenoids that contain a lactone ring hence the name They are found in many plants and can cause allergic reactions and toxicity if consumed excessively particularly in grazing livestock 8 The term merosesquiterpenoids was coined in 1968 to describe molecules of this class that have a mixed biosynthetic origin meaning isoprenoid precursors like isopentenyl pyrophosphate are derived from both the mevalonate and non mevalonate pathways 9 References Edit Eberhard Breitmaier 2006 Sesquiterpenes Terpenes Flavors Fragrances Pharmaca Pheromones pp 24 51 doi 10 1002 9783527609949 ch3 ISBN 9783527609949 https www science org doi 10 1126 sciadv adi5297 Davis Edward M Croteau Rodney 2000 Cyclization Enzymes in the Biosynthesis of Monoterpenes Sesquiterpenes and Diterpenes Topics in Current Chemistry 209 53 95 doi 10 1007 3 540 48146 X 2 ISBN 978 3 540 66573 1 Chizzola R 2013 Regular Monoterpenes and Sesquiterpenes Essential Oils Natural Products Springer Berlin Heidelberg pp 2973 3008 doi 10 1007 978 3 642 22144 6 130 ISBN 9783642221439 Katsui N Murai A Takasugi M Imaizumi K Masamune T amp Tomiyama K 1968 The structure of rishitin a new antifungal compound from diseased potato tubers Chemical Communications 1 43 https doi org 10 1039 c19680000043 D Harlingue A Mamdouh A M Malfatti P Soulie M C amp Bompeix G 1995 Evidence for rishitin biosynthesis in tomato cultures Phytochemistry 39 1 69 70 https doi org 10 1016 0031 9422 94 00844 J Izaguirre G Taylor WD June 1995 Geosmin and 2 methylisoborneol production in a major aqueduct system Water Science and Technology 31 11 41 48 doi 10 1016 0273 1223 95 00454 u Sesquiterpene Lactones and their toxicity to livestock Cornell CALS Cornell University Retrieved December 29 2018 Simpson Thomas J Ahmed Salman A Rupert McIntyre C Scott Fiona E Sadler Ian H 1997 03 17 Biosynthesis of polyketide terpenoid meroterpenoid metabolites andibenin B and andilesin A in Aspergillus variecolor Tetrahedron 53 11 4013 4034 doi 10 1016 S0040 4020 97 00015 X ISSN 0040 4020 External links Edit nbsp Look up sesquiterpene in Wiktionary the free dictionary Sesquiterpenes at the U S National Library of Medicine Medical Subject Headings MeSH Retrieved from https en wikipedia org w index php title Sesquiterpene amp oldid 1177930664, wikipedia, wiki, book, books, library,
