Isoamyl alcohol is a colorless liquid with the formula C 5H 12O, specifically (H3C–)2CH–CH2–CH2–OH. It is one of several isomers of amyl alcohol (pentanol). It is also known as isopentyl alcohol, isopentanol, or (in the IUPAC recommended nomenclature) 3-methyl-butan-1-ol. An obsolete name for it was isobutyl carbinol.[5]
Isoamyl alcohol is an ingredient in the production of banana oil, an ester found in nature and also produced as a flavouring in industry. It is a common fusel alcohol, produced as a major by-product of ethanol fermentation.
Occurrence
Isoamyl alcohol is one of the components of the aroma of Tuber melanosporum, the black truffle.
The compound has also been identified as a chemical in the pheromone used by hornets to attract other members of the hive to attack.[6]
Extraction from fusel oil
Isoamyl alcohol can be separated from fusel oil by either of two methods: shaking with strong brine solution and separating the oily layer from the brine layer; distilling it and collecting the fraction that boils between 125 and 140 °C. Further purification is possible with this procedure: shaking the product with hot limewater, separating the oily layer, drying the product with calcium chloride, and distilling it, collecting the fraction boiling between 128 and 132 °C.[5]
Besides its use in the synthesis of banana oil, isoamyl alcohol is also an ingredient of Kovac's reagent, used for the bacterial diagnostic indole test.
It is also used as an antifoaming agent in the chloroform isoamyl alcohol reagent.[7]
Isoamyl alcohol is used in a phenol–chloroform extraction mixed with the chloroform to further inhibit RNase activity and prevent solubility of RNAs with long tracts of poly-adenine.[8]
Drugs
IAA is also used as the reactant in the synthesis of the following list of drugs:
^Straka, M.; van Genderen, A.; Růžička, K.; Růžička, V. Heat Capacities in the Solid and in the Liquid Phase of Isomeric Pentanols. J. Chem. Eng. Data 2007, 52, 794-802.
^Wilson, Calum & Davies, Noel & Corkrey, Ross & J. Wilson, Annabel & M. Mathews, Alison & C. Westmore, Guy. (2017). Receiver Operating Characteristic curve analysis determines association of individual potato foliage volatiles with onion thrips preference, cultivar and plant age. PLOS ONE. 12. e0181831. 10.1371/journal.pone.0181831.
^Zumbo, P. "Phenol-chloroform Extraction"(PDF). WEILL CORNELL MEDICAL COLLEGE P. ZUMBO LABORATORY OF CHRISTOPHER E. MASON, PH.D. Retrieved 19 June 2014.