Category:TP3
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==Triterpene (C30) Biosynthesis== | ==Triterpene (C30) Biosynthesis== | ||
{{Twocolumn| | {{Twocolumn| | ||
| − | Triterpenes are formed by joining two FPPs tail-to-tail. The precursor compound of cholesterol (C27) is lanosterol (C30) for animals | + | Triterpenes are formed by joining two FPPs tail-to-tail. The precursor compound of cholesterol (C27) is lanosterol (C30) for animals. For plants, fungi and algae, it is almost cycloartenol with a trace of lanosterol-derived sterols<ref>Ohyama K, Suzuki M, Kikuchi J, Saito K, Muranaka T “Dual biosynthetic pathways to phytosterol via cycloartenol and lanosterol in Arabidopsis” Proc Natl Acad Sci USA 106(3):725-730, 2009</ref>. |
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==Steroid== | ==Steroid== | ||
| + | ===Ring configuration=== | ||
{{Twocolumn| | {{Twocolumn| | ||
| − | + | The basic steroid 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 bufadienolides, the rings C/D are ''cis''. | ||
| + | <br/> | ||
| + | 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. | ||
| + | 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. If the configuration at any site is unknown, it is indicated as ξ (Greek Xi). | ||
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| − | + | ステロイドの基本骨格は4つの環状構造で、シクロペンタ[a]フェナンスレン、ゴナン、ステランなどと呼ばれる。 | |
| + | 天然のステロイドでは環 B/C は常にトランスの位置にある。環 C/D がトランスの場合をゴナンと呼び、立体配置が指定されていないときをステランと呼ぶ。 | ||
| + | ほとんどのステロイドはゴナンの形をとるが、カルデノライドとブファジエノライドは環 C/D がシスになる。 | ||
| + | <br/> | ||
| + | 大多数のステロイドは橋頭位のC-10, C-13からメチル基が出ている。 | ||
| + | これらのメチル基 (または水素など) が平面より上に出ているときを、ベータ配置とする。平面より下の場合をアルファ配置とする。 | ||
| + | 原則として、C-8, 9, 10, 13, 14位にある水素や置換基はそれぞれ8β, 9α, 10β, 13β, 14α 配置である。 | ||
| + | C-5位は特別であり、5α のステロイドと 5β のものが同じくらい存在する。 | ||
| + | また、配置が不明な場合は、ξ (ギリシャ語の Xi)で表す。 | ||
}} | }} | ||
| + | <center> | ||
| + | {| style="text-align:center" | ||
| + | | [[Image:Cyclopenta-a-phenanthrene.png]] || [[Image:Gonane.png]] | ||
| + | |- | ||
| + | | Cyclopenta[a]phenanthrene || Gonane | ||
| + | |} | ||
| + | </center> | ||
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| + | ===Biosynthesis=== | ||
{| style="text-align:center; cellpadding:0" | {| style="text-align:center; cellpadding:0" | ||
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| − | == | + | ==Phytosterols== |
| + | {{Twocolumn| | ||
| + | Most common phytosterols are campesterol, β-sitosterol, and stigmasterol. Soybean ([[Species:Glycine|''Glycine max'']], [[:Category:Fabaceae|Fabaceae]]) is a rich source of phytosterols (about 0.1% of its weight), and is used for semi-synthesis of medicinal steroids <ref>Yamaya A, Endo Y, Fujimoto K, Kitamura K. “Effects of genetic variability and planting location on the phytosterol content and composition in soybean seeds” Food Chem 102(4): 1071-1075, 2006</ref>. Since dietary phytosterols reduce cholesterol levels, they are used as food additives such as for margarine <ref>Schiepers OJ, de Groot RH, van Boxtel MP, Jolles J, de Jong A, Lütjohann D, Plat J, Mensink RP “Consuming functional foods enriched with plant sterol or stanol esters for 85 weeks does not affect neurocognitive functioning or mood in statin-treated hypercholesterolemic individuals” J Nutr 139(7):1368-1373, 2009</ref>. Vitamin D is a family of sterol metabolites generated photochemically in our skin by UV irradiation. | ||
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| + | }} | ||
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| + | ==Saponins== | ||
{{Twocolumn| | {{Twocolumn| | ||
Saponins are surfactant glycosides, i.e., they produce foams in aqueous solution and therefore are called ‘sapo’ (a Latin for soap). Plant-based crude drugs are still actively prescribed in Eastern Asia, and many of their active components are attributed to saponins. Well known examples of saponin and its aglycone include glycyrrhizin from liquorice ([[Species:Glycyrrhiza|''Glycyrrhiza uralensis/glabra'']], [[:Category:Fabaceae]]) used in European confectionery and Asian medicine; ginsenosides from ginseng ([[Species:Panax|''Panax ginseng'']], [[:Category:Araliaceae|Araliaceae]]) for tonic, especially in Korea; diosgenin from wild yam ([[Species:Dioscorea|''Dioscorea spp.'']], [[:Category:Dioscoreaceae|Dioscoreaceae]]) for hormone replacement therapy. | Saponins are surfactant glycosides, i.e., they produce foams in aqueous solution and therefore are called ‘sapo’ (a Latin for soap). Plant-based crude drugs are still actively prescribed in Eastern Asia, and many of their active components are attributed to saponins. Well known examples of saponin and its aglycone include glycyrrhizin from liquorice ([[Species:Glycyrrhiza|''Glycyrrhiza uralensis/glabra'']], [[:Category:Fabaceae]]) used in European confectionery and Asian medicine; ginsenosides from ginseng ([[Species:Panax|''Panax ginseng'']], [[:Category:Araliaceae|Araliaceae]]) for tonic, especially in Korea; diosgenin from wild yam ([[Species:Dioscorea|''Dioscorea spp.'']], [[:Category:Dioscoreaceae|Dioscoreaceae]]) for hormone replacement therapy. | ||
Revision as of 19:14, 31 July 2010
Contents |
Triterpene (C30) Biosynthesis
Triterpenes are formed by joining two FPPs tail-to-tail. The precursor compound of cholesterol (C27) is lanosterol (C30) for animals. For plants, fungi and algae, it is almost cycloartenol with a trace of lanosterol-derived sterols[1].
Steroid
Ring configuration
The basic steroid 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 bufadienolides, the rings C/D are cis.
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.
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. If the configuration at any site is unknown, it is indicated as ξ (Greek Xi).
 |
|
| Cyclopenta[a]phenanthrene | Gonane |
Biosynthesis
 2,3-Oxidosqualene |
|
 ダンマラン (dammarane) 型 |
| ||
 Cholestane-type |
|
 Lanostane-type |
|
| ||
 Pregnane-type |
|
  Androstane- and Estrane-type |
Phytosterols
Most common phytosterols are campesterol, β-sitosterol, and stigmasterol. Soybean (Glycine max, Fabaceae) is a rich source of phytosterols (about 0.1% of its weight), and is used for semi-synthesis of medicinal steroids [2]. Since dietary phytosterols reduce cholesterol levels, they are used as food additives such as for margarine [3]. Vitamin D is a family of sterol metabolites generated photochemically in our skin by UV irradiation.
Saponins
Saponins are surfactant glycosides, i.e., they produce foams in aqueous solution and therefore are called ‘sapo’ (a Latin for soap). Plant-based crude drugs are still actively prescribed in Eastern Asia, and many of their active components are attributed to saponins. Well known examples of saponin and its aglycone include glycyrrhizin from liquorice (Glycyrrhiza uralensis/glabra, Category:Fabaceae) used in European confectionery and Asian medicine; ginsenosides from ginseng (Panax ginseng, Araliaceae) for tonic, especially in Korea; diosgenin from wild yam (Dioscorea spp., Dioscoreaceae) for hormone replacement therapy.
| 2,3-Oxidosqualene |
|
ダンマラン (dammarane) 型 |
| ring rearrangement
| ||
 Lupane-type |
|
 Baccharane-type |
|
| ||
 Oleanane-type |
|
 Taraxastane-type |
Design of Tri-terpene ID numbers ID番号の設計
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)
|
|
- 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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