Thujone Structure

The liqueur absinthe has been enjoying a resurgence in popularity, as countries continue to lift the ban on making and drinking the green anise-flavored spirit. Absinthe was banned in many places in the early part of the 20th century, purportedly because it is flavored with wormwood, which contains the terpene thujone. Thujone has medicinal applications, but is toxic in high concentrations. There had been reports of people going insane or experiencing hallucinations from drinking absinthe. The neurological symptoms were more likely the result of contamination of the distilling apparatus with heavy metals (also a concern when making moonshine), addition of copper salts to enhance the green coloration of some absinthes, and addition of antimony trichloride to enhance the louche effect of absinthe (the louche is the opalescent milkiness seen when water is added to the liqueur). Thujone flavors the non-banned drink, vermouth, and naturally occurs in the culinary herbs tarragon and sage.
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