4-Ethylphenol

4-Ethylphenol[1]
Other names p-Ethylphenol 1-Ethyl-4-hydroxybenzene 1-Hydroxy-4-ethylbenzene 4-hydroxyphenylethane
Identifiers
CAS number	123-07-9 Y
ChemSpider	28982 Y
UNII	AGG7E6G0ZC Y
KEGG	C13637 Y
ChEBI	CHEBI:49584 Y
ChEMBL	CHEMBL108475 Y
Jmol-3D images	Image 1
SMILES Oc1ccc(cc1)CC
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
Properties
Molecular formula	C8H10O
Molar mass	122.16 g/mol
Appearance	White solid
Melting point	42-45 °C
Boiling point	218 °C
Hazards
EU classification	Xi
S-phrases	S7/9 S26 S36/37/39 S45
NFPA 704	1 2 0
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox 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 (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.

Biochemistry

4-Ethylphenol is produced from the precursor p-coumaric acid. Brettanomyces converts this to 4-vinylphenol via the enzyme cinnamate decarboxylase.^[2] 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
• Wine fault
• Wine chemistry

References

1. ^ 4-Ethylphenol MSDS
2. ^ Brettanomyces Monitoring by Analysis of 4-ethylphenol and 4-ethylguaiacol at etslabs.com

External links

• 4-Ethylphenol oral toxicity data