4-Ethylguaiacol, often abbreviated to 4-EG, is a phenolic compound with the molecular formula C9H12O2. It can be produced in wine and beerbyBrettanomyces.[3] It is also frequently present in bio-oil produced by pyrolysisoflignocellulosic biomass.[4]
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| Names | |
|---|---|
| Preferred IUPAC name
4-Ethyl-2-methoxyphenol | |
| Other names
p-Ethylguaiacol | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider |
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| ECHA InfoCard | 100.018.637 
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C9H12O2 | |
| Molar mass | 152.193 g·mol−1 |
| Appearance | Colorless liquid |
| Density | 1064 kg/m3 (20 °C)[1] |
| Melting point | 15 °C (59 °F; 288 K) |
| Boiling point | 235.1 °C (455.2 °F; 508.2 K)[1] |
| Hazards | |
| GHS labelling:[2] | |
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| Warning | |
| H315, H319, H335 | |
| P302+P352, P305+P351+P338 | |
| NFPA 704 (fire diamond) | |
| Safety data sheet (SDS) | External MSDS |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
It is produced along with 4-ethylphenol (4-EP) in wine and beer by the spoilage yeast Brettanomyces.[3] When it is produced by the yeast to concentrations greater than the sensory threshold of >600 μg/L, it can contribute bacon, spice, clove, or smoky aromas to the wine. On their own these characters can be quite attractive in a wine, however as the compound usually occurs with 4-EP whose aromas can be more aggressive, the presence of the compound often signifies a wine fault. The ratio in which 4-EP and 4-EG are present can greatly affect the organoleptic properties of the wine.
4-Ethylguaiacol can also be produced by pyrolysisoflignocellulosic biomass. It is produced from the lignin, along with many of the other phenolic compounds present in bio-oil. In particular, 4-ethylguaiacol is derived from guaiacyl in the lignin.[4]
