Steviol

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Steviol
Steviol structure.svg
Identifiers
CAS number 471-80-7 N
PubChem 452967
ChemSpider 398979 YesY
UNII 4741LYX6RT YesY
ChEMBL CHEMBL444122 N
Jmol-3D images Image 1
Properties
Molecular formula C20H30O3
Molar mass 318.45 g mol−1
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Steviol is a diterpene first isolated from the plant Stevia rebaudiana in 1931.[1] Its chemical structure was not fully elucidated until 1960.[2]

Steviol occurs in the plant as steviol glycosides, sweet compounds that have found widespread use as sugar substitutes.[3]

Biosynthesis[edit]

In Stevia rebaudiana, the biosynthesis of steviol is confined to green tissues. The precursors of steviol are synthesized via the non-mevalonate pathway located in plant cell plastids, which produces isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). IPP and DMAPP are converted to geranylgeranyl diphosphate (GGDP), which is the precursor of many diterpenoids, by GGDP synthase. GPDP is made into a cyclic compound, copalyl diphosphate (CDP), by CDP synthase, after which kaurene is produced by another cyclization catalyzed by kaurene synthase.

The kaurene is then transferred to the endoplasmic reticulum, where it is oxidized to kaurenoic acid by kaurene oxidase in a reaction that uses up oxygen and NADPH. Then steviol is produced by hydroxylation. The steviol is subsequently glycosylated in the cytoplasm.[4]

Biosynthesis of steviol[4]

References[edit]

  1. ^ Bridel, M.; Lavieille, R. (1931). "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.". Bulletin de la Societe de Chimie Biologique 13: 781–796. 
  2. ^ Dolder, Fred; Lichti, Heinz; Mosettig, Erich; Quitt, Peter (1960). "The structure and stereochemistry of steviol and isosteviol". Journal of the American Chemical Society 82: 246–247. doi:10.1021/ja01486a054. 
  3. ^ J. E. Brandle, A. N. Starratt, M. Gijzen (1998), Stevia rebaudiana: Its agricultural, biological, and chemical properties. Canadian Journal of Plant Science, volume 78, issue 4, pages 527-536. doi:10.4141/P97-114
  4. ^ a b Brandle JE, Telmer PG. Steviol glycoside biosynthesis. Phytochemistry. 2007 Jul;68(14):1855-63. PMID: 17397883

External links[edit]