Terpenoid
The terpenoids, also known as isoprenoids, are a class of naturally occurring
Plant terpenoids are used for their aromatic qualities and play a role in traditional herbal remedies. Terpenoids contribute to the scent of
The
Structure and classification
Terpenoids are modified terpenes,[7] 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:
Terpenoids | Analogue terpenes | Number of isoprene units | Number of carbon atoms | General formula | Examples[8] |
---|---|---|---|---|---|
Hemiterpenoids
|
Isoprene | 1 | 5 | C5H8 | |
Monoterpenoids
|
Monoterpenes | 2 | 10 | C10H16 | Bornyl acetate, camphor, carvone, citral, citronellal, citronellol, geraniol, eucalyptol, hinokitiol, iridoids, linalool, menthol, thymol |
Sesquiterpenoids
|
Sesquiterpenes | 3 | 15 | C15H24 | Farnesol, geosmin, humulone |
Diterpenoids
|
Diterpenes | 4 | 20 | C20H32 | Abietic acid, ginkgolides, paclitaxel, retinol, salvinorin A, sclareol, steviol |
Sesterterpenoids
|
Sesterterpenes
|
5 | 25 | C25H40 | Andrastin A, manoalide |
Triterpenoids
|
Triterpenes | 6 | 30 | C30H48 | Amyrin, betulinic acid, limonoids, oleanolic acid, sterols, squalene, ursolic acid |
Tetraterpenoids
|
Tetraterpenes | 8 | 40 | C40H64 | Carotenoids |
Polyterpenoid
|
Polyterpenes | >8 | >40 | (C5H8)n | Gutta-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.
-
Paclitaxel is a diterpenoid anticancer drug.
-
Terpineols are monoterpenoids.
-
Humulones are classified as sesquiterpenoids.
-
Retinol is a diterpenoid.
-
Hinokitiol is a monoterpenoid, a tropolone derivative.
-
sesquiterpenoid.
Biosynthesis
Terpenoids, at least those containing an alcohol functional group, often arise by hydrolysis of carbocationic intermediates produced from
See also
- List of antioxidants in food
- List of phytochemicals in food
- Nutrition
- Phytochemistry
- Secondary metabolites
References
- .
- PMID 28841019.
- ^ Firn R (2010). Nature's Chemicals. Oxford: Biology.
- ISBN 9781444320503.
- ^ Specter M (September 28, 2009). "A Life of Its Own". The New Yorker.
- PMID 28324581.
- ^ Houghton, Isaac. "The Physiology of Cannabis Terpenes and Terpenoids – A Brief Overview". Elliot Barker. Retrieved 3 May 2016.
- ^ ISBN 9780128021040.
- hdl:1807/60332.
- ISBN 978-3-540-66573-1.