Surf Wiki
Save to docs
general/terpenes-and-terpenoids

From Surf Wiki (app.surf) — the open knowledge base

Terpenoid

Class of aromatic organic chemicals found in plants

Summary

Class of aromatic organic chemicals found in plants

The terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeably with "terpenes", terpenoids contain additional functional groups, usually containing oxygen. When combined with the hydrocarbon terpenes, terpenoids comprise about 80,000 compounds. They are the largest class of plant secondary metabolites, representing about 60% of known natural products. Many terpenoids have substantial pharmacological bioactivity and are therefore of interest to medicinal chemists.

Plant terpenoids are used for their aromatic qualities and play a role in traditional herbal remedies. Terpenoids contribute to the scent of eucalyptus, the flavors of cinnamon, cloves, and ginger, the yellow color in sunflowers, and the red color in tomatoes. Well-known terpenoids include citral, menthol, camphor, salvinorin A in the plant Salvia divinorum, ginkgolide and bilobalide found in Ginkgo biloba and the cannabinoids found in cannabis. The provitamin β-carotene (beta-carotene) is a terpene derivative called a carotenoid.

The steroids and sterols in animals are biologically produced from terpenoid precursors. Sometimes terpenoids are added to proteins, e.g., to enhance their attachment to the cell membrane; this is known as isoprenylation. Terpenoids play a role in plant defense as prophylaxis against pathogens and attractants for the predators of herbivores.

Structure and classification

Terpenoids are modified terpenes, wherein methyl groups have been moved or removed, or oxygen atoms added. Some authors use the term "terpene" more broadly, to include the terpenoids. Just like terpenes, the terpenoids can be classified according to the number of isoprene units that comprise the parent terpene:

TerpenoidsAnalogue terpenesNumber of isoprene unitsNumber of carbon atomsGeneral formulalast1=Ludwiczukfirst1=A.last2=Skalicka-Woźniakfirst2=K.last3=Georgievfirst3=M.I.title=Terpenoidsjournal=Pharmacognosydate=2017pages=233–266doi=10.1016/B978-0-12-802104-0.00011-1isbn=9780128021040 }}
HemiterpenoidsIsoprene15C5H8DMAPP, isopentenyl pyrophosphate, isoprenol, isovaleramide, isovaleric acid, HMBPP, prenol
MonoterpenoidsMonoterpenes210C10H16Bornyl acetate, camphor, carvone, citral, citronellal, citronellol, geraniol, eucalyptol, hinokitiol, iridoids, linalool, menthol, thymol
SesquiterpenoidsSesquiterpenes315C15H24Farnesol, geosmin, humulone
DiterpenoidsDiterpenes420C20H32Abietic acid, ginkgolides, paclitaxel, retinol, salvinorin A, sclareol, steviol
SesterterpenoidsSesterterpenes525C25H40Andrastin A, manoalide
TriterpenoidsTriterpenes630C30H48Amyrin, betulinic acid, limonoids, oleanolic acid, sterols, squalene, ursolic acid
TetraterpenoidsTetraterpenes840C40H64Carotenoids
PolyterpenoidPolyterpenes840(C5H8)nGutta-percha, natural rubber

Terpenoids can also be classified according to the type and number of cyclic structures they contain: linear, acyclic, monocyclic, bicyclic, tricyclic, tetracyclic, pentacyclic, or macrocyclic.

File:Taxol.svg|Paclitaxel is a diterpenoid anticancer drug. File:Terpineol alpha.svg|Terpineols are monoterpenoids. File:(S)-Humulone.svg|Humulones are classified as sesquiterpenoids. File:All-trans-Retinol2.svg|Retinol is a diterpenoid. File:Beta-thujaplicin.png|Hinokitiol is a monoterpenoid, a tropolone derivative. File:Limonin.svg|Limonin, a common limonoid, is a triterpenoid. File:Geosmin_Structural_Formulae.svg|Geosmin is a sesquiterpenoid.

Biosynthesis

Terpenoids, at least those containing an alcohol functional group, often arise by hydrolysis of carbocationic intermediates produced from geranyl pyrophosphate. Analogously hydrolysis of intermediates from farnesyl pyrophosphate gives sesquiterpenoids, and hydrolysis of intermediates from geranylgeranyl pyrophosphate gives diterpenoids, etc.

Impact on aerosols

In air, terpenoids are converted into various species, such as aldehydes, hydroperoxides, organic nitrates, and epoxides by short-lived free radicals (like the hydroxyl radical) and to a lesser extent by ozone. These new species can dissolve into water droplets and contribute to aerosol and haze formation. Secondary organic aerosols formed from this pathway may have atmospheric impacts.

As an example the Blue Ridge Mountains in the U.S. and Blue Mountains of New South Wales in Australia are noted for having a bluish color when seen from a distance. Trees put the "blue" in Blue Ridge, from their terpenoids released into the atmosphere.

References

References

  1. Chemistry, International Union of Pure and Applied. "IUPAC Compendium of Chemical Terminology". IUPAC.
  2. (2017). "Structural and Chemical Biology of Terpenoid Cyclases". Chemical Reviews.
  3. Firn, Richard. (2010). "Nature's Chemicals". Oxford: Biology.
  4. (2010). "Biochemistry of Plant Secondary Metabolism".
  5. Specter, Michael. (September 28, 2009). "A Life of Its Own".
  6. (April 2015). "Plant terpenes: defense responses, phylogenetic analysis, regulation and clinical applications". [[3 Biotech]].
  7. "The Physiology of Cannabis Terpenes and Terpenoids – A Brief Overview". Elliot Barker.
  8. (2017). "Terpenoids". Pharmacognosy.
  9. (2008). "Phytochemical Screening and Antioxidant Activities of Some Selected Medicinal Plants Used for Malaria Therapy in Southwestern Nigeria". Tropical Journal of Pharmaceutical Research.
  10. (2000). "Cyclization Enzymes in the Biosynthesis of Monoterpenes, Sesquiterpenes, and Diterpenes". Topics in Current Chemistry.
  11. [https://www.sciencedaily.com/releases/2009/08/090806141518.htm Organic Carbon Compounds Emitted By Trees Affect Air Quality], ScienceDaily, Aug. 7, 2009
  12. IUPAC Subcommittee on Gas Kinetic Data Evaluation – [http://www.iupac-kinetic.ch.cam.ac.uk/datasheets/pdf/Ox_VOC7_O3_CH2C%28CH3%29CHCH2.pdf Data Sheet Ox_VOC7], 2007
  13. [https://www.sciencenews.org/article/source-haze A source of haze], ScienceNews, August 6, 2009
  14. (2019-09-05). "Chamber-based insights into the factors controlling epoxydiol (IEPOX) secondary organic aerosol (SOA) yield, composition, and volatility". Atmospheric Chemistry and Physics.
  15. (1998). "Invitation To Organic Chemistry". Jones & Bartlett Learning.
  16. (2007). "Blue Ridge Parkway, Frequently Asked Questions". National Park Service.
  17. CSIRO. "Beating the eucalypt blues – new ways to model air quality".
Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

terpenes-and-terpenoids plant-communication
Want to explore this topic further?

Ask Mako anything about Terpenoid — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report