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Lanosterol
IUPAC name	lanosta-8,24-dien-3-ol
Identifiers
CAS number	79-63-0 Y
PubChem	4861
MeSH	Lanosterol
SMILES	C[C@H](CCC=C(C)C)[C@H]1CC [C@]2(C)C1CCC3=C2CC[C@H] 4C(C)(C)[C@@H](O)CC[C@]34C
Properties
Molecular formula	C30H50O
Molar mass	426.71 g/mol
Exact mass	426.386166
Melting point	138-140 °C
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Lanosterol is a tetracyclic triterpenoid, which is the compound from which all steroids are derived.

Role in creation of steroids

Elaboration of lanosterol under enzyme catalysis leads to the core structure of steroids. 14-Demethylation of lanosterol by CYP51 eventually yields cholesterol.

Simplified version of the lanosterol synthesis pathway with the intermediates isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP), and squalene shown. Some intermediates are omitted.

Biosynthesis

Description	Illustration	Enzyme
Two molecules of farnesyl pyrophosphate condense with reduction by NADPH to form squalene		squalene synthase
Squalene is oxidized to 2,3-oxidosqualene (squalene epoxide)		squalene monooxygenase
2,3-Oxidosqualene is converted to a protosterol cation and finally to lanosterol		lanosterol synthase
(step 2)		(step 2)

See also

• Cycloartenol
• CYP51

References

• E. J. Corey, W. E. Russey, P. R. Ortiz de Montellano (1966). "2,3-Oxidosqualene, an Intermediate in the Biological Synthesis of Sterols from Squalene". Journal of the American Chemical Society 88 (20): 4750–4751. doi:10.1021/ja00972a056.  
• I. Abe, M. Rohmer, G. D. Prestwich (1993). "Enzymatic cyclization of squalene and oxidosqualene to sterols and triterpenes". Chemical Reviews 93 (6): 2189–2206. doi:10.1021/cr00022a009.  
• A. Eschenmoser, L. Ruzicka, O. Jeger, D. Arigoni (1955). "Zur Kenntnis der Triterpene. 190. Mitteilung. Eine stereochemische Interpretation der biogenetischen Isoprenregel bei den Triterpenen". Helvetica Chimica Acta 38 (7): 1890–1904. doi:10.1002/hlca.19550380728.  

External links