Linalool (/lɪˈnæloʊˌɒl, laɪ-, –loʊˌɔːl, –ləˌwɒl, –ləˌwoʊl/ or /ˌlɪnəˈluːl/) refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. These have multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of spiciness). It has other names such as β-linalool, linalyl alcohol, linaloyl oxide, p-linalool, allo-ocimenol, and 3,7-dimethyl-1,6-octadien-3-ol.
Over 200 species of plants produce linalool, mainly from the families Lamiaceae (mint and other herbs), Lauraceae (laurels, cinnamon, rosewood), and Rutaceae (citrus fruits), but also birch trees and other plants, from tropical to boreal climate zones, including fungi.
In higher plants, linalool, as other monoterpenoids, is produced from isopentenyl pyrophosphate via the universal isoprenoid intermediate geranyl pyrophosphate, through a class of membrane-bound enzymes named monoterpene synthases. One of these, linalool synthase (LIS), has been reported to produce (S)-linalool in several floral tissues.
In addition, linalool is used by pest professionals as a flea, fruit fly and cockroach insecticide. It can also be used a method of pest control for codling moths. Linalool create a synergistic effect with the codling moth’s phermone called codlemone, which increases attraction of males.
Linalool is used in some mosquito-repellent products; however, the EPA notes that “a preliminary screen of labels for products containing [l]inalool (as the sole active ingredient) indicates that efficacy data on file with the Agency may not support certain claims to repel mosquitos.”
Plants that contain linalool
- Cinnamomum tamala
- Cannabis sativa
- Cannabis indica
- Ocimum basilicum
- Solidago Meyen, Solidago chilensis
- Artemisia vulgaris (mugwort)
- Humulus lupulus
Safety and potential toxicity
Linalool can be absorbed by inhalation of its aerosol and by oral intake or skin absorption, potentially causing irritation, pain and allergic reactions. Between 5% and 7% of patients undergoing patch testing in Sweden were found to be allergic to the oxidized form of linalool. Upon inhalation, it may also cause drowsiness or dizziness.