Category:TP3
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| squalene | | squalene | ||
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| − | | 2,3-oxidosqualene | + | |colspan="2"| 2,3-oxidosqualene |
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| [[Image:squalene.png]] | | [[Image:squalene.png]] | ||
| − | | | + | | [[Image:Arrow00r.png]] |
| − | | [[Image:2,3-oxidosqualene.png]] | + | |colspan="2"|[[Image:2,3-oxidosqualene.png]] |
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| − | | [[Image: | + | | [[Image:Arrow00d35.png]] |
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| + | | [[Image:Arrow00dl35.png]] | ||
| + | | [[Image:Arrow00dr35.png]] | ||
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| + | | [[Image:Deoxydammarenyl cation.png]] | ||
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| − | + | | [[Image:Protosteryl cation.png]] | |
| − | + | | [[Image:Dammarenyl cation.png]] | |
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| − | | [[Image: | + | |
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| − | | [[Image: | + | |
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| − | | [[Image: | + | | [[Image:Hopyl cation.png]] |
| − | | [[Image: | + | | |
| + | | [[Image:Lanosteryl cation.png]] | ||
| + | | [[Image:Baccarenyl cation.png]] | ||
| + | |- | ||
| + | | [[Image:Hopene.png]] | ||
| + | | | ||
| + | | [[Image:Lanosterol.png]] | ||
| + | | [[Image:Lupeol.png]] | ||
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Revision as of 15:29, 5 August 2010
Contents |
Triterpene (C30) Classes
Ring configuration
The basic structure is 4 carbon rings, cyclopenta[a]phenanthrene, gonane, or sterane. The rings B/C are always trans in all natural steroids. If the rings C/D are trans, it is called gonane. If its stereochemistry is unspecified, it is called sterane. Most steroids take gonane form, but in cardenolides and bufanolides, the rings C/D are cis.
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| Cyclopenta[a]phenanthrene | Gonane |
The majority of steroids have methyl groups sticking out from the bridgehead positions C-10 and C-13. When these methyl groups (or hydrogens) stand above the plane, they are called β-configuration. Those below the plane are called α-configuration. If the configuration at any site is unknown, it is indicated as ξ (Greek Xi). By default, hydrogen atoms or substituents at the positions C-8, 9, 10, 13, and 14 are assumed to be 8β, 9α, 10β, 13β, and 14α configurations. C-5 is a special position, because there are as many 5α steroids as 5β are.
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| cholestane backbone | 5α-configuration | 5β-configuration |
Biosynthesis
The starting point is squalene, which is formed by joining two FPPs tail-to-tail. In bacteria, squalene is cyclized via the 17α-deoxydammarenyl cation to hopene and other triterpenes. In eukaryotes, 2,3-oxidosqualene is cyclized via the protosteryl cation to lanosterol or cycloartenol by a series of 1,2-hydride and methyl shifts (Wagner-Meerwein shifts). Plant triterpenes arise from the dammarenyl cation. This molecule undergoes cyclization to form either the protosterol cation (through chair-boat cyclization) or the dammarenyl cation (through chair-chair cyclization). From the protosterol cation, lanosterol or cycloartenol occurs. From the 17β-dammarenyl cation, dammarane and other plant triterpenoids occur. From the 17α-damarenyl cation, hopanoids occur.
- animals, fungi, and yeast
- 2,3-oxidosqualene → lanosterol
- plants (including algae)
- 2,3-oxidosqualene → cycloartenol, dammarane
- bacteria
- 2,3-oxidosqualene → hopene
Cyclization
| squalene | 2,3-oxidosqualene | ||
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Design of Tri-terpene ID numbers ID番号の設計
<center> 12-DIGIT
| T | P | 3 | x | y | y | r | h | g | n | c | c |
- x ... species information
| Symbol at x | Kingdom | Phyla | Examples |
|---|---|---|---|
| I | Animalia | Arthropoda (Insects, crabs) | ecdysteroids |
| V | Chordate (Vertebrates) | sex steroids, corticosteroids, anabolic steroids | |
| O | Others | marine steroids | |
| P | Plantae | Phytosterols | lanosterols, cholesterols, brassinolides |
| S | Saponins | saponins | |
| F | Fungi | ergosterols | ergosterols |
| B | Bacteria | bacterial sterols | hopanoids |
- y ... backbone structure (母核構造)
| Symbol at y | Carbons | Steroids | Backbone Structure |
|---|---|---|---|
| GN | C17 | gonane |
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| ES | C18 | estrane | 
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| AD | C19 | androstane | 
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| PG | C21 | pregnane | 
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| CA | C24 | cholane | 
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| CL | C27 | cholestane |
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| CM | C28 | campestane | 
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| EG | C28 | ergostane | 
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| SG | C29 (4 rings) | stigmastane | 
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| PR | C29 (4 rings) | poriferastane | 
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| Symbol at y | Carbons | Triterpenoids | Backbone Structure |
|---|---|---|---|
| PS | C30 | protostane | 
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| EU | C30 | euphane | 
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| LN | C30 | lanostane | 
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| CY | C30 | cycloartane | 
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| FS | C29 | fusidane | 
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| HP | C30 (5 rings) | hopane | 
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| FN | C30 (5 rings) | fernane | 
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| CC | C30 | cucurbitane | 
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| DM | C30 | dammarane | 
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| BC | C30 | baccharane | 
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| HL | C30 | holostane | 
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| PF | C29 (5 rings) | pfaffane | 
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| LP | C30 (5 rings) | lupane | 
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| OL | C30 (5 rings) | oleanane | 
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| FD | C30 (5 rings) | friedelane | 
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| TR | C30 (5 rings) | taraxastane | 
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| UR | C30 (5 rings) | ursane | 
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| SR | C30 (5 rings) | serratane | 
|
- r ... number of major rings (環構造数)
Click above categories to see details.
- h ... hydroxylation pattern (水酸基数)
Click above categories to see details.
- g ... glycosylation pattern(糖修飾パターン)
Click above categories to see details.
- n ... number of sugars (修飾糖数)
Click above categories to see details.
- c ... serial number (通し番号)
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