1-Octen-3-ol

1-Octen-3-ol, octenol for short and also known as mushroom alcohol, is a chemical that attracts biting insects such as mosquitoes. It is contained in human breath and sweat, and it is believed that insect repellent DEET works by blocking the insects' octenol odorant receptors.

The name "mushroom alcohol" for 1-octen-3-ol comes from it first isolation by S. Murahashi in 1936 and 1938 from crushed matsutake mushrooms. A recent study on volatiles of this mushroom has shown this compound is only produced upon tissue disruption. This alcohol is found in many other mushrooms where it may play a role as an antifeedant.

Natural occurrence

Octenol is produced by several plants and fungi, including edible mushrooms and lemon balm. Octenol is formed during oxidative breakdown of linoleic acid. Octenol is responsible for the moldy odor of damp indoor environments.

It is also a wine fault, defined as a cork taint, occurring in wines made with bunch rot contaminated grape.

Properties

1-octen-3-ol is a secondary alcohol derived from 1-octene. It exists in the form of two enantiomers, (R)-(−)-1-octen-3-ol and (S)-(+)-1-octen-3-ol.

File:(RS)-1-Octen-3-ol FormulaV1.svg

The two enantiomers of 1-octen-3-ol

Synthesis

Two possible lab syntheses of 1-octen-3-ol are:

• by the Grignard reaction of acrolein and amyl iodide
• by the selective reduction of 1-octen-3-one

Biochemically, 1-octen-3-ol is generated from the peroxidation of linoleic acid, catalyzed by a lipoxygenase, followed by cleavage of the resulting hydroperoxide with the help of a hydroperoxide lyase. This reaction takes place in cheese and is used in biotechnology to produce the (R)-isomer.

File:Octenol-biosynthesis.png

Biosynthesis of (R)-1-octen-3-ol: 1) linoleic acid, 2) (8E,12Z)-10-hydroperoxyoctadecadienoic acid, 3) (R)-1-octen-3-ol, 4) (8E)-10-oxodecenoic acid, 5) lipoxygenase, 6) hydroperoxide lyase.

Uses

Octenol is used, sometimes in combination with carbon dioxide, to attract insects in order to kill them with certain electrical devices.

The name 'mushroom alcohol' is used because octenol is the main flavor component of mushrooms.

Health and safety

Octenol is approved by the U.S. Food and Drug Administration as a food additive. It is of moderate toxicity with an LD₅₀ of 340 mg/kg.

In an animal study, octenol has been found to disrupt dopamine homeostasis and may be an environmental agent involved in parkinsonism.

See also

• Olfactory receptor
• Oct-1-en-3-one, the ketone analog that gives blood on skin its typical metallic, mushroom-like smell
• 1-Octen-3-yl acetate, the acetate ester of this compound