Each enantiomer evokes distinct neural responses in humans, so each is classified as possessing distinct
scents. (S)-(+)-Linalool is perceived as sweet, floral,
petitgrain-like (odor threshold 7.4
ppb) and the (R)-form as more woody and
lavender-like (odor threshold 0.8
ppb).
In
higher plants linalool is formed by rearrangement of
geranyl pyrophosphate (GPP).[12] With the aid of
linalool synthase (LIS), water attacks to form the chiral center.[13][12] LIS appears to show a
limonene synthase-type catalysis through a simplified "metal-cofactor-binding domain [where the majority] of the residues involved in substrate...binding [are] in the C-terminal part of the protein" suggesting
stereoselectivity and the reasoning behind why some plants have varying levels of each enantiomer.[14][15]
Odor and flavor
Linalool has complex odor and flavor properties. Its odor is similar to floral, spicy wood, somewhat resembling
French lavender plants,
bergamot oil or
lily of the valley.[1] It has a light, citrus-like flavor, sweet with a spicy tropical accent.[1] Linalool is used as a scent in
perfumed hygiene products and cleaning agents, including
soaps,
detergents,
shampoos, and lotions.[1][2] It exhibits antimicrobial and antifungal properties.[1][16]
Chemical derivatives
Linalool is hydrogenated to give dihydro- and tetrahydrolinalool, which are fragrances that are more resilient toward oxidants, as might be found in household cleaning products.
Linalyl acetate, a popular scent, is produced by esterification of linalool (as well as occurring naturally). Isomerization of linalool gives
geraniol and
nerol.[17]
Safety
Linalool can be absorbed by inhalation of its
aerosol and by oral intake or skin absorption, potentially causing irritation, pain and
allergic reactions.[2][18] Some 7% of people undergoing
patch testing in Europe were found to be allergic to the
oxidized form of linalool.[19]
The US Food and Drug Administration (FDA) lists linalool in the Code of Federal Regulations under substances generally recognized as safe, synthetic flavoring substances and adjuvants. [20]
^Kasper S, Gastpar M, Müller WE, Volz HP, Möller HJ, Dienel A, Schläfke S (September 2010). "Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, placebo controlled trial". International Clinical Psychopharmacology. 25 (5): 277–87.
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^Ibrahim EA, Wang M, Radwan MM, Wanas AS, Majumdar CG, Avula B, et al. (March 2019). "Analysis of Terpenes in Cannabis sativa L. Using GC/MS: Method Development, Validation, and Application". Planta Medica. 85 (5): 431–438.
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^Klimankova E, Holadová K, Hajšlová J, Čajka T, Poustka J, Koudela M (2008). "Aroma profiles of five basil (Ocimum basilicum L.) cultivars grown under conventional and organic conditions". Food Chemistry. 107 (1): 464–472.
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^Vila R, Mundina M, Tomi F, Furlán R, Zacchino S, Casanova J, Cañigueral S (February 2002). "Composition and antifungal activity of the essential oil of Solidago chilensis". Planta Medica. 68 (2): 164–7.
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^Albert Eschenmoser: "Leopold Ruzicka - From the Isoprene Rule to the Question of Life's Origin" CHIMIA 44 (1990)
^"Linalool". Toxnet, National Library of Medicine, US National Institutes of Health. 14 January 2016. Archived from
the original on 28 February 2019. Retrieved 21 May 2019.
^Ung CY, White JM, White IR, Banerjee P, McFadden JP (March 2018). "Patch testing with the European baseline series fragrance markers: a 2016 update". The British Journal of Dermatology. 178 (3): 776–780.
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