|Preferred IUPAC name
p-Ethylphenol (no longer recommended)
3D model (Jmol)
|Molar mass||122.16 g/mol|
|Melting point||42 to 45 °C (108 to 113 °F; 315 to 318 K)|
|Boiling point||218 °C (424 °F; 491 K)|
EU classification (DSD)
|S-phrases||S7/9 S26 S36/37/39 S45|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
4-Ethylphenol, often abbreviated to 4-EP, is a phenolic compound.
In wine and beer, it is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold (140 µg/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-ethylphenol.
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.
- 4-Ethylphenol MSDS
- Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 690. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
Only one name is retained, phenol, for C6H5-OH, both as a preferred name and for general nomenclature. The structure is substitutable at any position. Locants 2, 3, and 4 are recommended, not o, m, and p.
- Brettanomyces Monitoring by Analysis of 4-ethylphenol and 4-ethylguaiacol at etslabs.com