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4-Ethylphenol



4-Ethylphenol
Other names p-Ethylphenol
1-Ethyl-4-hydroxybenzene
1-Hydroxy-4-ethylbenzene
4-hydroxyphenylethane
Identifiers
CAS number 123-07-9
SMILES CCC1=CC=C(C=C1)O
Properties
Molecular formula C8H10O
Molar mass 122.16
Appearance white solid
Melting point

42 - 45°C

Boiling point

218°C

Hazards
EU classification Error creating thumbnail: Xi
NFPA 704
1
2
0
 
S-phrases S7/9, S26, S36/37/39, S45
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

4-Ethylphenol, often abbreviated to 4-EP is a phenolic compound with the molecular formula C8H10O. 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 aromas described as barnyard, medicinal, band-aids, 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. 4-vinylphenol is further reduced to 4-ethylphenol by the enzyme vinyl phenol reductase. Coumaric acid is sometimes added to microbiological media, enabling the positive identification of Brettanomyces by smell.

 

See also

References

     
    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "4-Ethylphenol". A list of authors is available in Wikipedia.
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