Taraxasterol
This article relies largely or entirely on a single source. (January 2018) |
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IUPAC name
18α,19α-Urs-20(30)-en-3β-ol
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Preferred IUPAC name
(3S,4aR,6aR,6bR,8aR,12S,12aR,12bR,14aR,14bR)-4,4,6a,6b,8a,12,14b-Heptamethyl-11-methylidenedocosahydropicen-3-ol | |
Other names
Anthesterin
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Identifiers | |
3D model (JSmol)
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ChEBI | |
ChEMBL | |
ChemSpider | |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C30H50O | |
Molar mass | 426.729 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
what is ?) | (|
Infobox references | |
Taraxasterol (anthesterin) is a triterpene derived from the mevalonate pathway and is found in dandelions.[1]
Biosynthesis[]
The precursor for the biosynthesis of taraxasterol is squalene. In the first step of this formation squalene is cyclized with molecular oxygen, FAD, and NADPH via the enzyme squalene epoxidase a flavoprotein to yield (2S)-2,3-oxidosqualene. In the second step if the oxidosqualene is folded in the chair conformation in the enzyme a cascade of cyclizations will occur that results in the formation of the dammarenyl cation.[1]
The dammarenyl cation is then subjected to an alkyl shift to create a six-membered ring and relieving ring strain to form the baccharenyl cation. This allows the baccharenyl double bond to attack the secondary positive charge and forms a pentacyclic ring system to yield the tertiary lupanyl cation. A Wagner-Meerwein 1,2-alykl shift will occur to form the hexacyclic ring system and the secondary oleanyl cation. This is followed by a Wagner-Meerwein 1,2-methyl shift to create the tertiary taraxasteryl cation. This cation is the last intermediate in the taraxasterol pathway. An E2 reaction follows where deprotonation of a proton yields taraxasterol. The enzymes involved in this biosynthesis are oxidosesqualene: lupeopl cyclase and oxidosqualene: B-amyrin cyclase.[1]
Dammarenyl cation
Taraxasterol synthesis
References[]
- Triterpenes
- Secondary alcohols