4-Ethylphenol
4330316
189011492
2008-02-04T12:22:45Z
Edgar181
491706
ref and layout cleanup
{{Chembox new
| Reference=<ref>[http://physchem.ox.ac.uk/MSDS/ET/4-ethylphenol.html 4-Ethylphenol MSDS]</ref>
| Name = 4-Ethylphenol
| ImageFile = 4-ethylphenol.svg
| OtherNames = ''p''-Ethylphenol<br />1-Ethyl-4-hydroxybenzene<br />1-Hydroxy-4-ethylbenzene<br />4-hydroxyphenylethane
| Section1 = {{Chembox Identifiers
| SMILES = CCC1=CC=C(C=C1)O
| CASNo = 123-07-9
| RTECS =
}}
| Section2 = {{Chembox Properties
| Formula = C<sub>8</sub>H<sub>10</sub>O
| MolarMass = 122.16 g/mol
| Appearance = White solid
| Solvent = solvent
| MeltingPt = 42-45 °C
| BoilingPt = 218 °C
}}
| Section7 = {{Chembox Hazards
| EUClass = {{Hazchem_Xi}}
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| SPhrases = {{S36}}, {{S37}}
| SPhrases = {{S7/9}}, {{S26}}, {{S36/37/39}}, {{S45}}
}}
}}
'''4-Ethylphenol''', often abbreviated to '''4-EP''' is a [[phenolic]] compound with the molecular formula C<sub>8</sub>H<sub>10</sub>O. In [[wine]] and [[beer]] it is produced by the spoilage [[yeast]] ''[[Brettanomyces]]''. When it reaches concentrations greater than the [[sensory threshold]] (140µg/L) it can give the wine [[aroma]]s described as ''barnyard'', ''medicinal'', ''[[band-aid]]s'', and ''mousy''. In certain Belgian beer styles, a high 4-EP level may be desirable; however, very high levels of the compound in wine can render it undrinkable. The level of 4-ethylphenol is roughly proportional to ''Brettanomyces'' concentration and activity, and can therefore be used as an indicator of the yeast's presence. There are significant differences between strains of Brettanomyces in their ability to produce 4-Ethyl Phenol.
==Biochemistry==
4-Ethylphenol is produced from the precursor [[p-coumaric acid]]. ''Brettanomyces'' converts this to [[4-vinylphenol]] via the enzyme [[cinnamate decarboxylase]].<ref>[http://www.etslabs.com/scripts/ets/pagetemplate/blank.asp?pageid=193 Brettanomyces Monitoring by Analysis of 4-ethylphenol and 4-ethylguaiacol] at etslabs.com</ref> 4-Vinylphenol is further reduced to 4-ethylphenol by the enzyme [[vinyl phenol reductase]]. Coumaric acid is sometimes added to [[growth medium|microbiological media]], enabling the positive identification of ''Brettanomyces'' by smell.
[[Image:Coumaric acid to 4-ethyphenol.png|left|thumb|290px|The conversion of [[p-coumaric acid]] to 4-ethyphenol by Brettanomyces]]<br style="clear:left;"/>
==See also==
*[[4-Ethylguaiacol]]
*[[Brettanomyces]]
*[[Wine fault]]
==References==
<references/>
==External links==
*[http://wwwdb.mhlw.go.jp/ginc/cgi-bin/db1_search.pl?CAS=123-07-9&MID=177 4-Ethylphenol oral toxicity data]
{{DEFAULTSORT:Ethylphenol, 4-}}
[[Category:Phenols]]
[[Category:oenology]]