Thujon

Thujones form a weakly yellowish, clear liquid. They form a group of bicyclic monoterpenes (monoterpene ketones) with a menthol-like odor. The molecular formula is: C10H16O.

Thujones are found in Thuja occidentalis, thyme, wormwood, rain fern, rosemary, water mint, mugwort, pole mint and in the true sage, among others. These plants are used as spices for drinks and food (see below).

In Artemisia absinthium (wormwood) alpha- and beta-thujones are detected. Thuja oil contains about 50-60% alpha- and beta- thujone, rain fern oil about 60% beta- thujone.

Thujones are poisonous substances (poison class 3 of the Swiss poison list). They act neurotoxic (Pelkonen O et al. 2013) and inhibit the receptor for gamma-aminobutyric acid A (GABA). In higher doses they cause confusion and convulsions (Roth L et al. 1994). Other symptoms such as dizziness, hallucinations and delusions can also be observed.

Medicine: Thujone-containing topicals have antimycotic effects (fungicidal effects on dermatophytes), as shown by alpha- and beta-thujone-containing extracts of Artemisia sieberi (Mahboubi M et al. 2015)

Cosmetics: In the cosmetic field, thujone is used as a fragrance.

In 1791, Mr. Pernod improved the recipe of Absinthe (primarily pure alcohol): to pure alcohol were added herbs like wormwood, mugwort, rue, Pontic wormwood and diptam. Anise and fennel were added to determine the taste.

1. Mahboubi M et al (2015) The antifungal activity of Artemisia sieberi essential oil from different localities of Iran against dermatophyte fungi.J Mycol Med 25:e65-71.
2. Pelkonen O et al (2013) Thujone and thujone-containing herbal medicinal and botanical products:toxicological assessment. Regul Toxicol Pharmacol 65:100-1007.
3. Roth L et al. (1994) Toxic plants and plant toxins. Nikol Publishing Company, Hamburg S 941-942