4-Ethylphenol

4-Ethylphenol[1]
P-Ethylphenol.svg
Names
Preferred IUPAC name

4-Ethylphenol[2]
Other names

p-Ethylphenol
1-Ethyl-4-hydroxybenzene
1-Hydroxy-4-ethylbenzene
4-Hydroxyphenylethane
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.181
EC Number 204-598-6
KEGG
UNII
Properties
C8H10O
Molar mass 122.167 g·mol−1
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)
Hazards
GHS pictograms The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H314, H318
P260, P264, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P363, P405, P501
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no code

NFPA 704 four-colored diamond

1
2
0
Flash point 104 °C (219 °F; 377 K)
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 (4-EP) is a phenolic compound.

Natural occurrences[edit]

In wine and beer, 4-EP 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-EP 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-EP.

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

Biochemistry[edit]

4-EP is produced from the precursor p-coumaric acid. Brettanomyces converts this to 4-vinylphenol via the enzyme cinnamate decarboxylase.[3] 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-EP by Brettanomyces

See also[edit]

References[edit]

  1. ^ 4-Ethylphenol MSDS[permanent dead link]
  2. ^ 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.
  3. ^ Brettanomyces Monitoring by Analysis of 4-ethylphenol and 4-ethylguaiacol Archived 2008-02-19 at the Wayback Machine at etslabs.com

External links[edit]