Ergosterol

Chembox new
ImageFile = Ergosterol structure.svg
ImageSize = 250px
IUPACName = (3"S",9"S",10"R",13"R",14"R",17"R")-17-((2"R",5"R","E")-5,6-
dimethylhept-3-en-2-yl)-10,13-
dimethyl-2,3,4,9,10,11,12,13,14,15,16,17-
dodecahydro-1"H"-cyclopenta ["a"] phenanthren-3-ol
OtherNames =
Section1 = Chembox Identifiers
CASNo = 57-87-4
PubChem =
SMILES = CC(C) [C@@H] (C)C=C [C@@H]
(C) [C@H] 1CC [C@H] 2C3=C
C=C4C [C@@H] (O)CC [C@] 4
(C) [C@H] 3CC [C@] 12C
InChI=1/C28H44O/c1-18(2) 19(3)7-8-20(4)24-11-12- 25-23-10-9-21-17-22(29) 13-15-27(21,5)26(23)14- 16-28(24,25)6/h7-10, 18-20,22,24-26,29H,11- 17H2,1-6H3/b8-7+/t19-, 20+,22-,24+,25-,26-, 27-,28+/m0/s1
MeSHName = Ergosterol
Section2 = Chembox Properties
Formula = C₂₈H₄₄O
MolarMass = 396.66 g/mol
Appearance =
Density =
MeltingPt = 160.0 °C
BoilingPt = 250.0 °C
Section3 = Chembox Hazards
Solubility =
MainHazards =
FlashPt =
Autoignition =

Ergosterol (ergosta-5,7,22-trien-3β-ol), a sterol, is a biological precursor (a provitamin) to Vitamin D₂. It is turned into viosterol by ultraviolet light, and is then converted into ergocalciferol, which is a form of Vitamin D. [cite journal |author=Rajakumar K, Greenspan SL, Thomas SB, Holick MF |title=SOLAR ultraviolet radiation and vitamin D: a historical perspective |journal=Am J Public Health |volume=97 |issue=10 |pages=1746–54 |year=2007 |month=October |pmid=17761571 |doi=10.2105/AJPH.2006.091736 |url=http://www.ajph.org/cgi/pmidlookup?view=long&pmid=17761571]

Ergosterol is a component of fungal cell membranes, serving the same function that cholesterol serves in animal cells. The presence of ergosterol in fungal cell membranes coupled with its absence in animal cell membranes makes it a useful target for antifungal drugs. Ergosterol is also present in the cell membranes of some protists, such as trypanosomes. [cite journal |author=Roberts CW, McLeod R, Rice DW, Ginger M, Chance ML, Goad LJ |title=Fatty acid and sterol metabolism: potential antimicrobial targets in apicomplexan and trypanosomatid parasitic protozoa |journal=Mol. Biochem. Parasitol. |volume=126 |issue=2 |pages=129–42 |year=2003 |month=February |pmid=12615312 |doi=10.1016/S0166-6851(02)00280-3] This is the basis for the use of some antifungals against West African sleeping sickness.

Amphotericin B is an antifungal drug that targets ergosterol. It binds to ergosterol and creates a polar pore in fungal membranes. This causes ions (predominantly K⁺ and H⁺) and other molecules to leak out, which will kill the cell. [cite journal |author=Ellis D |title=Amphotericin B: spectrum and resistance |journal=J. Antimicrob. Chemother. |volume=49 Suppl 1 |issue= |pages=7–10 |year=2002 |month=February |pmid=11801575 |url=http://jac.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=11801575 |doi=10.1093/jac/49.suppl_1.7 |doi_brokendate=2008-07-02] Amphotericin B has been replaced by safer agents in most circumstances but is still used, despite its side effects, for life-threatening fungal infections. Miconazole and Clotrimazole also inhibit synthesis of ergosterol.

Ergosterol is also used as an indicator of fungal biomass in soil. Though ergosterol does degrade over time, if kept below freezing in a dark environment, this degradation can be slowed or even stopped completely.

References

External links

[http://ptcl.chem.ox.ac.uk/MSDS/ER/ergosterol.html Safety (MSDS) data for ergosterol] Oxford University (2005)