View source for Chemistry:Steviol

{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 470470860
| ImageFile = steviol structure.svg
| ImageSize = 200px
| ImageFile1     = Steviol-3D ball-and-stick.png
| ImageSize1     = 
| IUPACName = 13-Hydroxy-5β,8α,9β,10α,13α-kaur-16-en-18-oic acid
| SystematicName = (4''R'',4a''S'',6a''R'',9''S'',11a''R'',11b''S'')-9-Hydroxy-4,11b-dimethyl-8-methylidenetetradecahydro-6a,9-methanocyclohepta[''a'']naphthalene-4-carboxylic acid
| OtherNames = Hydroxydehydrostevic acid<br>13-Hydroxykaurenoic acid<br>''ent''-13-Hydroxykaur-16-en-19-oic acid
|Section1={{Chembox Identifiers
| CASNo = 471-80-7
| CASNo_Ref = {{cascite|changed|??}}
| PubChem = 452967
| ChemSpiderID = 398979
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChEBI = 145024
| ChEMBL = 444122      
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 4741LYX6RT
| SMILES = O=C(O)[C@]4([C@H]3CC[C@@]21C[C@](O)(\C(=C)C1)CC[C@H]2[C@]3(C)CCC4)C
| InChI = 1/C20H30O3/c1-13-11-19-9-5-14-17(2,7-4-8-18(14,3)16(21)22)15(19)6-10-20(13,23)12-19/h14-15,23H,1,4-12H2,2-3H3,(H,21,22)/t14-,15-,17+,18+,19+,20-/m0/s1
| InChIKey = QFVOYBUQQBFCRH-VQSWZGCSBR
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C20H30O3/c1-13-11-19-9-5-14-17(2,7-4-8-18(14,3)16(21)22)15(19)6-10-20(13,23)12-19/h14-15,23H,1,4-12H2,2-3H3,(H,21,22)/t14-,15-,17+,18+,19+,20-/m0/s1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = QFVOYBUQQBFCRH-VQSWZGCSSA-N
  }}
|Section2={{Chembox Properties
| C=20 | H=30 | O=3
| Appearance = 
| Density = 
| MeltingPt = 
| BoilingPt = 
| Solubility =
  }}
|Section3={{Chembox Hazards
| MainHazards = 
| FlashPt = 
| AutoignitionPt =
  }}
}}

'''Steviol''' is a [[Chemistry:Diterpene|diterpene]] first isolated from the plant ''[[Biology:Stevia rebaudiana|Stevia rebaudiana]]'' in 1931.<ref name=brid1931/>  Its chemical structure was not fully elucidated until 1960.<ref name=dolder1960/>

Steviol occurs in the plant as [[Chemistry:Steviol glycoside|steviol glycoside]]s, sweet compounds that have found widespread use as [[Chemistry:Sugar substitute|sugar substitute]]s.<ref name=brandleCJPS98/> The aglycon is prepared by enzymatic hydrolysis, since upon acid treatment steviol will undergo Wagner-Meerwein rearrangement to the very stable isosteviol.

==Biosynthesis==
In ''Stevia rebaudiana'', the [[Biology:Biosynthesis|biosynthesis]] of steviol is confined to green tissues.  The precursors of steviol are synthesized via the [[Biology:Non-mevalonate pathway|non-mevalonate pathway]] located in plant cell plastids, which produces [[Chemistry:Isopentenyl pyrophosphate|isopentenyl pyrophosphate]] (IPP) and [[Chemistry:Dimethylallyl pyrophosphate|dimethylallyl pyrophosphate]] (DMAPP). IPP and DMAPP are converted to geranylgeranyl diphosphate (GGDP), which is the precursor of many [[Biology:Terpenoid|diterpenoids]], by [[Biology:Farnesyltranstransferase|GGDP synthase]].  GPDP is made into a [[Physics:Cyclic compound|cyclic compound]], copalyl diphosphate (CDP), by [[Biology:Copalyl diphosphate synthase|CDP synthase]], after which kaurene is produced by another cyclization catalyzed by [[Biology:Ent-kaurene synthase|kaurene synthase]].

The kaurene is then transferred to the endoplasmic reticulum, where it is oxidized to [[Chemistry:Kaurenoic acid|kaurenoic acid]] by [[Biology:Ent-kaurenoic acid oxidase|kaurene oxidase]] in a reaction that uses up oxygen and NADPH.   Then steviol is produced by hydroxylation. The steviol is subsequently [[Biology:Glycosylation|glycosylated]] in the cytoplasm.<ref name=brandle2007/>
{{clear left}}[[File:Bio synthesis of steviol glycoside 01.png|thumb|600px|center|Biosynthesis of steviol<ref name=brandle2007/>]]{{clear}}

==References==
<references>

<ref name=brandleCJPS98>{{cite journal | author = Brandle J. E., Starratt A. N., Gijzen M. | year = 1998 | title = Stevia rebaudiana: Its agricultural, biological, and chemical properties | journal = Canadian Journal of Plant Science | volume = 78 | issue = 4| pages = 527–536 | doi = 10.4141/P97-114 | doi-access = free }}</ref>

<ref name=brid1931>{{cite journal |author1=Bridel, M. |author2=Lavieille, R. | title = The sweet principle in Kaa-he-e (Stevia rebaudiana. Bertoni). II. Hydrolysis of stevioside by enzymes. III. Steviol by enzymic hydrolysis and isosteviol by acid hydrolysis.    | journal = Bulletin de la Société de Chimie Biologique | year = 1931 | pages = 781–796 | volume = 13}}</ref>

<ref name=brandle2007>{{cite journal | author = Brandle JE, Telmer PG | date = Jul 2007 | title = Steviol glycoside biosynthesis | journal = Phytochemistry | volume = 68 | issue = 14| pages = 1855–63 | pmid = 17397883 | doi = 10.1016/j.phytochem.2007.02.010 | bibcode = 2007PChem..68.1855B }}</ref>

<ref name=dolder1960>{{cite journal |author1=Dolder, Fred |author2=Lichti, Heinz |author3=Mosettig, Erich |author4=Quitt, Peter | title = The structure and stereochemistry of steviol and isosteviol | journal = Journal of the American Chemical Society | year = 1960 | volume = 82  | pages = 246–247 | doi = 10.1021/ja01486a054}}</ref>
</references>

==External links==
* [https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=598381 PubChem summary of steviol molecule]

[[Category:Diterpenes]]
[[Category:Cyclopentanes]]
[[Category:Vinylidene compounds]]

{{Sourceattribution|Steviol}}