Absinthe historically contains thujone; which category does thujone belong to?

• A. Alcohols
• B. Proteins
• C. Terpenoids
• D. Carbohydrates

Answer: (C)

Thujone is a terpenoid because it is built from isoprene units and appears as an oxygenated derivative of a terpene, specifically a monoterpene ketone. Terpenoids are a broad family of plant metabolites found in essential oils, and thujone’s structure and origin in wormwood fit this category. It isn’t an alcohol, protein, or carbohydrate—those have hydroxyl-containing molecules, peptide chains, or sugar units, respectively. The terpene/terpenoid framework explains why thujone belongs in this group.