4-Ethylphenol

4-Ethylphenol

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Names
Other names p-Ethylphenol 1-Ethyl-4-hydroxybenzene 1-Hydroxy-4-ethylbenzene 4-hydroxyphenylethane
Identifiers
CAS Number	123-07-9 Y
ChEBI	CHEBI:49584 Y
ChEMBL	ChEMBL108475 Y
ChemSpider	28982 Y
Jmol 3D model	Interactive image
KEGG	C13637 Y
UNII	AGG7E6G0ZC Y
InChI InChI=1S/C8H10O/c1-2-7-3-5-8(9)6-4-7/h3-6,9H,2H2,1H3 Y Key: HXDOZKJGKXYMEW-UHFFFAOYSA-N Y InChI=1/C8H10O/c1-2-7-3-5-8(9)6-4-7/h3-6,9H,2H2,1H3 Key: HXDOZKJGKXYMEW-UHFFFAOYAF
SMILES Oc1ccc(cc1)CC
Properties
Chemical formula	C8H10O
Molar mass	122.16 g/mol
Appearance	White solid
Melting point	42 to 45 °C (108 to 113 °F; 315 to 318 K)
Boiling point	218 °C (424 °F; 491 K)
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

4-Ethylphenol, often abbreviated to 4-EP, is a phenolic compound.

Natural occurrences

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.

It is also a component of castoreum, the exudate from the castor sacs of the mature North American beaver (Castor canadensis) and the European beaver (Castor fiber), used in perfumery.

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.

The conversion of p-coumaric acid to 4-ethyphenol by Brettanomyces

See also

• 4-Ethylguaiacol
• Yeast in winemaking
• Wine fault
• Wine chemistry
• List of additives in cigarettes

External links

• 4-Ethylphenol oral toxicity data