Linalool () refers to two

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

s of a naturally occurring

terpene Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n ≥ 2. Terpenes are major biosynthetic building blocks. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predomi ...

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

found in many

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s and

spice In the culinary arts, a spice is any seed, fruit, root, Bark (botany), bark, or other plant substance in a form primarily used for flavoring or coloring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of pl ...

plants. Together with

geraniol Geraniol is a monoterpenoid and an alcohol. It is the primary component of citronella oil and is a primary component of rose oil and palmarosa oil. It is a colorless oil, although commercial samples can appear yellow. It has low solubility i ...

nerol Nerol is a monoterpenoid alcohol found in many essential oils such as lemongrass and hops. It was originally isolated from neroli oil, hence its name. This colourless liquid is used in perfumery. Like geraniol, nerol has a sweet rose odor but it ...

, and citronellol, linalool is one of the rose alcohols. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of spiciness). A colorless oil, linalool is classified as an acyclic

monoterpenoid Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen funct ...

. In plants, it is a

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

, a

volatile oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

component, an

antimicrobial An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used aga ...

agent, and an

aroma compound An aroma compound, also known as an odorant, aroma, fragrance, flavoring or flavor, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficien ...

. Linalool has uses in manufacturing of soaps, fragrances,

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...

s as flavors, household products, and

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

Ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s of linalool are referred to as linalyl, e.g. linalyl

pyrophosphate In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate () and tetrasodium pyrophosphate (), among others. Often pyrophosphates a ...

, an isomer of

geranyl pyrophosphate Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), is the pyrophosphate ester of the terpenoid geraniol. Its salts are colorless. It is a precursor to many thousands of natural product, natural products. Occurrence GPP is an int ...

. The word ''linalool'' is based on '' linaloe'' (a type of wood) and the suffix '. In food manufacturing, it may be called ''coriandrol''.

Occurrence

Linalool Enantiomers Structural Formulae

Both

ic forms are found in nature: (''S'')-linalool is found, for example, as a major constituent of the essential oils of

coriander Coriander (), whose leaves are known as cilantro () in the U.S. and parts of Canada, and dhania in parts of South Asia and Africa, is an annual plant, annual herb (''Coriandrum sativum'') in the family Apiaceae. Most people perceive the ...

(''

Coriandrum sativum Coriander (), whose leaves are known as cilantro () in the U.S. and parts of Canada, and dhania in parts of South Asia and Africa, is an annual herb (''Coriandrum sativum'') in the family Apiaceae. Most people perceive the leaves as ha ...

'' L.),

cymbopogon ''Cymbopogon'', also known as lemongrass, barbed wire grass, silky heads, oily heads, Cochin grass, Malabar grass, citronella grass or fever grass, is a genus of Asian, African, Australian, and tropical island plants in the Poaceae, grass famil ...

('' Cymbopogon martini'' var. ''martinii''), and

sweet orange The orange, also called sweet orange to distinguish it from the bitter orange (''Citrus × aurantium''), is the fruit of a tree in the family Rutaceae. Botanically, this is the hybrid ''Citrus'' × ''sinensis'', between the pomelo (''Citrus ...

(''

Citrus sinensis ''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Mandarin orange, mandarins, lemons, grapefruits, ...

'') flowers. (''R'')-linalool is present in

lavender ''Lavandula'' (common name lavender) is a genus of 47 known species of perennial flowering plants in the sage family, Lamiaceae. It is native plant, native to the Old World, primarily found across the drier, warmer regions of the Mediterranean ...

('' Lavandula officinalis''),

bay laurel ''Laurus nobilis'' is an aromatic evergreen tree or large shrub with green, glabrous (smooth) leaves. It is in the flowering plant family Lauraceae. According to Flora Cretica (Kleinsteuber Books, 2024, ISBN 978-3-9818110-5-6) the stem can be 1 ...

(''Laurus nobilis''), and sweet basil (''Ocimum basilicum''), among others. Each enantiomer evokes distinct neural responses in humans, so each is classified as possessing distinct

scent An odor (American English) or odour (English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is a smell or a scent caused by one or more volatilized ...

s. (''S'')-(+)-Linalool is perceived as sweet, floral,

petitgrain Petitgrain () is an essential oil that is extracted from the leaves and green twigs of the bitter orange tree (''Citrus aurantium'' ssp. ''amara'') via steam distillation. It is also known as petitgrain bigarade. Etymology Petitgrain (Fr.: � ...

-like (odor threshold 7.4 ppb) and the (''R'')-form as more woody and

-like (odor threshold 0.8 ppb). Over 200 species of plants produce linalool, notably from the families

Lamiaceae The Lamiaceae ( ) or Labiatae are a family (biology), family of flowering plants commonly known as the mint, deadnettle, or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil (herb), ba ...

(

mint Mint or The Mint may refer to: Plants * Lamiaceae, the mint family ** ''Mentha'', the genus of plants commonly known as "mint" Coins and collectibles * Mint (facility), a facility for manufacturing coins * Mint condition, a state of like-new ...

and other herbs),

Lauraceae Lauraceae, or the laurels, is a plant Family (biology), family that includes the bay laurel, true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genus (biology), genera worldwide. They are dicotyled ...

(

laurels ''Laurus nobilis'' is an aromatic evergreen tree or large shrub with green, glabrous (smooth) leaves. It is in the flowering plant family Lauraceae. According to Flora Cretica (Kleinsteuber Books, 2024, ISBN 978-3-9818110-5-6) the stem can be 1 ...

cinnamon Cinnamon is a spice obtained from the inner bark of several tree species from the genus ''Cinnamomum''. Cinnamon is used mainly as an aromatic condiment and flavouring additive in a wide variety of cuisines, sweet and savoury dishes, biscuits, b ...

rosewood Rosewood is any of a number of richly hued hardwoods, often brownish with darker veining, but found in other colours. It is hard, tough, strong, and dense. True rosewoods come from trees of the genus '' Dalbergia'', but other woods are often ca ...

), and

Rutaceae The Rutaceae () is a family (biology), family, commonly known as the rueRUTACEAE
in Bo ...

(

citrus fruits ''Citrus'' is a genus of flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, mandarins, lemons, grapefruits, pomelos, and limes. ''Citrus'' is native to S ...

), but also birch trees and other plants, from

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

boreal climate The subarctic climate (also called subpolar climate, or boreal climate) is a continental climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of ...

zones. * '' Aniba rosaeodora'' * ''

Lavandula ''Lavandula'' (common name lavender) is a genus of 47 known species of perennial flowering plants in the sage family, Lamiaceae. It is native to the Old World, primarily found across the drier, warmer regions of the Mediterranean, with an affi ...

'' * ''

Cinnamomum tamala ''Cinnamomum tamala'', Indian bay leaf'','' also known as tejpat'', ''tejapatta'','' Malabar leaf, Indian bark, Indian cassia, or malabathrum, is a tree in the family Lauraceae that is native to northern India (Assam and the Western Himalayas), ...

'' * ''

Cannabis sativa ''Cannabis sativa'' is an annual Herbaceous plant, herbaceous flowering plant. The species was first classified by Carl Linnaeus in 1753. The specific epithet ''Sativum, sativa'' means 'cultivated'. Indigenous to East Asia, Eastern Asia, the pla ...

'' * ''

Basil Basil (, ; , ; ''Ocimum basilicum'' (, )), also called great basil, is a culinary herb of the family Lamiaceae (mints). It is a hardiness (plants), tender plant, and is used in cuisines worldwide. In Western cuisine, the generic term "basil" r ...

'' * ''

Solidago ''Solidago'', commonly called goldenrods, is a genus of about 100 to 120''Solidago''.
F ...

'' (goldenrod) * ''

Artemisia vulgaris ''Artemisia vulgaris'', commonly known as mugwort, common mugwort, or wormwood, is a species of flowering plant in the daisy family Asteraceae. It is one of several species in the genus '' Artemisia'' commonly known as mugwort, although ''Art ...

'' (mugwort) * ''

Humulus lupulus ''Humulus lupulus'', the common hop or hops, is a species of flowering plant in the hemp family, Cannabaceae. It is a perennial, herbaceous climbing plant which sends up new shoots in early spring and dies back to a cold-hardy rhizome in autumn. ...

'' (hop) It was first synthesized in the laboratory of

Leopold Ružička Leopold Ružička (; born Lavoslav Stjepan Ružička; 13 September 1887 – 26 September 1976) was a Croatian-Swiss scientist and joint winner of the 1939 Nobel Prize in Chemistry "for his work on polymethylenes and higher terpenes" "including ...

in 1919.Albert Eschenmoser: "Leopold Ruzicka - From the Isoprene Rule to the Question of Life's Origin" CHIMIA 44 (1990)

Production

Linalool is produced commercially from several terpenes and terpenoid precursors, which are often components of terpentine. 2-Pinanol, derived from

pinene Pinene is a collection of unsaturated bicyclic monoterpenes. Two geometric isomers of pinene are found in nature, α-pinene and β-pinene. Both are chiral. As the name suggests, pinenes are found in pines. Specifically, pinene is the major comp ...

, gives

linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Together with geraniol, nerol, and citronellol, linalool is one of the rose alcohols. Linalool has multiple commercial app ...

upon pyrolysis.

Biosynthesis

higher plants Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue ( ...

linalool is formed by rearrangement of

(GPP). With the aid of linalool synthase (LIS), water attacks to form the chiral center. LIS appears to show a limonene synthase-type catalysis through a simplified "metal-cofactor-binding domain here the majorityof the residues involved in substrate...binding rein the C-terminal part of the protein" suggesting

stereoselectivity In chemistry, stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereoisomers during a non- stereospecific creation of a new stereocenter or during a non-stereospecific transformation ...

and the reasoning behind why some plants have varying levels of each enantiomer. Linalool_Biosynthesis

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 Lily of the valley (''Convallaria majalis'' ), sometimes written lily-of-the-valley, is a woodland flowering plant with sweetly scented, pendent, bell-shaped white flowers borne in sprays in spring. It is native throughout the cool temperate No ...

. It has a light, citrus-like flavor, sweet with a spicy tropical accent. Linalool is used as a scent in

perfume Perfume (, ) is a mixture of fragrance, fragrant essential oils or aroma compounds (fragrances), Fixative (perfumery), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agre ...

d hygiene products and cleaning agents, including

soap Soap is a salt (chemistry), salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually u ...

detergent A detergent is a surfactant or a mixture of surfactants with Cleanliness, cleansing properties when in Concentration, dilute Solution (chemistry), solutions. There are a large variety of detergents. A common family is the alkylbenzene sulfonate ...

shampoo Shampoo () is a hair care product, typically in the form of a viscous liquid, that is formulated to be used for cleaning (scalp) hair. Less commonly, it is available in solid bar format. (" Dry shampoo" is a separate product.) Shampoo is use ...

s, and lotions. It exhibits antimicrobial and antifungal properties.

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 Linalyl acetate is an organic compound, the acetate ester of linalool and a phytochemical found in many flowers and spice plants. It is one of the principal components of the essential oils of bergamot and lavender. It often occurs together wit ...

, a popular scent, is produced by esterification of linalool (as well as occurring naturally). Isomerization of linalool gives

and

Safety

Linalool can be absorbed by inhalation of its

aerosol An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be generated from natural or Human impact on the environment, human causes. The term ''aerosol'' co ...

and by oral intake or skin absorption, potentially causing irritation, pain and

allergic Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, alle ...

reactions. Some 7% of people undergoing

patch test A patch test is a diagnostic method used to determine which specific substances cause allergic inflammation of a patient's skin. Patch testing helps identify which substances may be causing a delayed-type allergic reaction in a patient and ...

ing in Europe were found to be allergic to the oxidized form of linalool. 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.

References

External links

Comprehensive data sheet
* {{Transient receptor potential channel modulators Flavors Tertiary alcohols Plant toxin insecticides Alkene derivatives Monoterpenes Perfume ingredients

Occurrence

Production

Biosynthesis

Odor and flavor

Chemical derivatives

Safety

See also

References

External links