linalool

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 470609278

| ImageFile = Linalool skeletal.svg

| ImageSize = 240

| ImageAlt = Skeletal formula

| ImageFile1 = (S)-Linalool molecule ball.png

| ImageSize1 = 240

| ImageAlt1 = Ball-and-stick model

| PIN = 3,7-Dimethylocta-1,6-dien-3-ol

| OtherNames = 3,7-Dimethyl-1,6-octadien-3-ol, β-linalool, linalyl alcohol, linaloyl oxide, allo-ocimenol, coriandrol, Licareol

|Section1={{Chembox Identifiers

| index_label =

| index1_label = (R)

| index2_label = (S)

| index_comment = (±)-linalool

| index1_comment = (−)-linalool

| index2_comment = (+)-linalool

| testQID = Q410932

| QID1 = Q27105200

| QID2 = Q27105233

| IUPHAR_ligand = 2469

| CASNo = 78-70-6

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo1 = 126-91-0

| CASNo1_Ref = {{cascite|correct|CAS}}

| CASNo2 = 126-90-9

| CASNo2_Ref = {{cascite|correct|CAS}}

| PubChem = 6549

| PubChem1 = 443158

| PubChem2 = 67179

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 25306

| ChEMBL2 = 235672

| KEGG1 = C11388

| KEGG2 = C11389

| 3DMet = B05103

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = D81QY6I88E

| UNII1_Ref = {{fdacite|correct|FDA}}

| UNII1 = 3U21E3V8I2

| UNII2_Ref = {{fdacite|correct|FDA}}

| UNII2 = F4VNO44C09

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 13849981

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 17580

| ChEBI1 = 28

| ChEBI2 = 98

| InChI = 1/C10H18O/c1-5-10(4,11)8-6-7-9(2)3/h5,7,11H,1,6,8H2,2-4H3

| InChIKey = CDOSHBSSFJOMGT-UHFFFAOYAV

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C10H18O/c1-5-10(4,11)8-6-7-9(2)3/h5,7,11H,1,6,8H2,2-4H3

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = CDOSHBSSFJOMGT-UHFFFAOYSA-N

| SMILES = CC(O)(C=C)CCC=C(C)C

}}

|Section2={{Chembox Properties

| C=10|H=18|O=1

| Appearance = Colorless oil

| Density = 0.858 to 0.868 g/cm³

| MeltingPt= <

| MeltingPtC = −20

| BoilingPtC = 198 to 199

| BoilingPt_notes =

| Solubility = 1.589 g/l

}}

|Section3={{Chembox Hazards

| NFPA-H = 1

| NFPA-F = 2

| NFPA-R = 0

| MainHazards =

| FlashPtC = 55

| AutoignitionPtC =

}}

Linalool ({{IPAc-en|l|ᵻ|ˈ|n|æ|l|oʊ|ɒ|l|,_|l|aɪ|-|,_|-|l|oʊ|oʊ|l|,_|-|ˈ|l|uː|l}}) refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants.{{cite web |title=Linalool |url=https://pubchem.ncbi.nlm.nih.gov/compound/6549 |publisher=PubChem, US National Library of Medicine |access-date=17 October 2021 |date=16 October 2021}} Together with geraniol, nerol, 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).{{Ullmann |doi=10.1002/14356007.a26_205|title=Terpenes|year= 2000|last1=Eggersdorfer|first1=Manfred}}{{cite journal |doi=10.1016/S0278-6915(03)00015-2|title=Fragrance material review on linalool|year=2003|last1=Letizia|first1=C.S|last2=Cocchiara|first2=J.|last3=Lalko|first3=J.|last4=Api|first4=A.M|journal=Food and Chemical Toxicology|volume=41|issue=7|pages=943–964|pmid=12804650}}

A colorless oil, linalool is classified as an acyclic monoterpenoid. In plants, it is a metabolite, a volatile oil component, an antimicrobial agent, and an aroma compound. Linalool has uses in manufacturing of soaps, fragrances, food additives as flavors, household products, and insecticides. Esters of linalool are referred to as linalyl, e.g. linalyl pyrophosphate, an isomer of geranyl pyrophosphate.{{cite journal |pmid=3392006|year=1988|last1=Croteau|first1=R.|last2=Satterwhite|first2=D. M.|last3=Cane|first3=D. E.|last4=Chang|first4=C. C.|title=Biosynthesis of Monoterpenes. Enantioselectivity in the Enzymatic Cyclization of (+)- and (-)-Linalyl Pyrophosphate to (+)- and (-)-Pinene and (+)- and (-)-Camphene|journal=The Journal of Biological Chemistry|volume=263|issue=21|pages=10063–71|doi=10.1016/S0021-9258(19)81477-1 |doi-access=free }}

The word linalool is based on linaloe (a type of wood) and the suffix {{linktext|-ol}}.{{Merriam-Webster|Linalool}}: "International Scientific Vocabulary, from Mexican Spanish lináloe" In food manufacturing, it may be called coriandrol.

Occurrence

File:Linalool Enantiomers Structural Formulae.png

Both enantiomeric forms are found in nature: (S)-linalool is found, for example, as a major constituent of the essential oils of coriander (Coriandrum sativum L.), cymbopogon (Cymbopogon martini var. martinii), and sweet orange (Citrus sinensis) flowers. (R)-linalool is present in lavender (Lavandula officinalis), bay laurel (Laurus nobilis), and sweet basil (Ocimum basilicum), among others.

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).

Over 200 species of plants produce linalool, notably 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.

Aniba rosaeodora
Lavandula{{cite journal | vauthors = Kasper S, Gastpar M, Müller WE, Volz HP, Möller HJ, Dienel A, Schläfke S | title = Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, placebo controlled trial | journal = International Clinical Psychopharmacology | volume = 25 | issue = 5 | pages = 277–87 | date = September 2010 | pmid = 20512042 | doi = 10.1097/YIC.0b013e32833b3242 | s2cid = 46290020 }}
Cinnamomum tamala{{cite journal | vauthors = Ahmed A, Choudhary MI, Farooq A, Demirci B, Demirci F, Can Başer KH | title = Essential oil constituents of the spice Cinnamomum tamala (Ham.) Nees & Eberm. | journal = Flavour and Fragrance Journal | volume = 15 | issue = 6 | pages = 388–390 | year = 2000 | doi = 10.1002/1099-1026(200011/12)15:6<388::AID-FFJ928>3.0.CO;2-F | doi-access = free }}
Cannabis sativa{{cite journal | vauthors = Ibrahim EA, Wang M, Radwan MM, Wanas AS, Majumdar CG, Avula B, Wang YH, Khan IA, Chandra S, Lata H, Hadad GM, Abdel Salam RA, Ibrahim AK, Ahmed SA, ElSohly MA | display-authors = 6 | title = Analysis of Terpenes in Cannabis sativa L. Using GC/MS: Method Development, Validation, and Application | journal = Planta Medica | volume = 85 | issue = 5 | pages = 431–438 | date = March 2019 | pmid = 30646402 | doi = 10.1055/a-0828-8387 | bibcode = 2019PlMed..85..431I | s2cid = 58668648 }}
Basil{{cite journal | vauthors = Klimankova E, Holadová K, Hajšlová J, Čajka T, Poustka J, Koudela M | title = Aroma profiles of five basil (Ocimum basilicum L.) cultivars grown under conventional and organic conditions | journal = Food Chemistry | volume = 107 | issue = 1 | pages = 464–472 | year = 2008 | doi = 10.1016/j.foodchem.2007.07.062 }}
Solidago (goldenrod){{cite journal | vauthors = Vila R, Mundina M, Tomi F, Furlán R, Zacchino S, Casanova J, Cañigueral S | title = Composition and antifungal activity of the essential oil of Solidago chilensis | journal = Planta Medica | volume = 68 | issue = 2 | pages = 164–7 | date = February 2002 | pmid = 11859470 | doi = 10.1055/s-2002-20253 | bibcode = 2002PlMed..68..164V | s2cid = 260283973 }}
Artemisia vulgaris (mugwort)
Humulus lupulus (hop)

It was first synthesized in the laboratory of Leopold Ružička 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, gives linalool upon pyrolysis.{{Ullmann |doi=10.1002/14356007.a26_205|title=Terpenes |year=2000 |last1=Eggersdorfer |first1=Manfred |isbn=3527306730 }}

=Biosynthesis=

In higher plants linalool is formed by rearrangement of geranyl pyrophosphate (GPP).{{cite journal | vauthors = Woronuk G, Demissie Z, Rheault M, Mahmoud S | title = Biosynthesis and therapeutic properties of Lavandula essential oil constituents | journal = Planta Medica | volume = 77 | issue = 1 | pages = 7–15 | date = January 2011 | pmid = 20665367 | doi = 10.1055/s-0030-1250136 | doi-access = free | bibcode = 2011PlMed..77....7W }} With the aid of linalool synthase (LIS), water attacks to form the chiral center.{{cite book |last1=Dewick |first1=Paul M | name-list-style = vanc |title=Medicinal Natural Products: A Biosynthetic Approach |date=2009 |publisher=John Wiley & Sons |isbn=978-0-470-74168-9 |edition=3rd}} 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.{{cite journal | vauthors = Cseke L, Dudareva N, Pichersky E | title = Structure and evolution of linalool synthase | journal = Molecular Biology and Evolution | volume = 15 | issue = 11 | pages = 1491–8 | date = November 1998 | pmid = 12572612 | doi = 10.1093/oxfordjournals.molbev.a025876 | doi-access = free }}{{cite journal | vauthors = Iijima Y, Davidovich-Rikanati R, Fridman E, Gang DR, Bar E, Lewinsohn E, Pichersky E | title = The biochemical and molecular basis for the divergent patterns in the biosynthesis of terpenes and phenylpropenes in the peltate glands of three cultivars of basil | journal = Plant Physiology | volume = 136 | issue = 3 | pages = 3724–36 | date = November 2004 | pmid = 15516500 | pmc = 527170 | doi = 10.1104/pp.104.051318 | doi-access = free }}

File:Linalool_Biosynthesis.png pathway. Abbreviations used: geranyl diphosphate synthase (GDS), pyrophosphate ester (OPP), isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP). Stereogenic centers are indicated by an asterisk.|654x654px]]

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. It has a light, citrus-like flavor, sweet with a spicy tropical accent. Linalool is used as a scent in perfumed hygiene products and cleaning agents, including soaps, detergents, shampoos, and lotions. It exhibits antimicrobial and antifungal properties.{{cite journal |doi=10.1016/j.foodchem.2007.12.010|title=Chemical composition, antioxidant and antimicrobial activities of basil (Ocimum basilicum) essential oils depends on seasonal variations|year=2008|last1=Hussain|first1=Abdullah Ijaz|last2=Anwar|first2=Farooq|last3=Hussain Sherazi|first3=Syed Tufail|last4=Przybylski|first4=Roman|journal=Food Chemistry|volume=108|issue=3|pages=986–995|pmid=26065762}}

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.{{cite book |doi=10.1002/0471238961.2005181602120504.a01.pub2|chapter=Terpenoids |title=Kirk-Othmer Encyclopedia of Chemical Technology |year=2006 |last1=Sell |first1=Charles S. |isbn=0471238961 }}

Safety

Linalool can be absorbed by inhalation of its aerosol and by oral intake or skin absorption, potentially causing irritation, pain and allergic reactions.{{cite web |title=Linalool |url=https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+645 | archive-url = https://web.archive.org/web/20190228004550/https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+645 | archive-date = 28 February 2019 |publisher=Toxnet, National Library of Medicine, US National Institutes of Health |access-date=21 May 2019 |date=14 January 2016}} Some 7% of people undergoing patch testing in Europe were found to be allergic to the oxidized form of linalool.{{cite journal | vauthors = Ung CY, White JM, White IR, Banerjee P, McFadden JP | title = Patch testing with the European baseline series fragrance markers: a 2016 update | journal = The British Journal of Dermatology | volume = 178 | issue = 3 | pages = 776–780 | date = March 2018 | pmid = 28960261 | doi = 10.1111/bjd.15949 | s2cid = 4434234 }}

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.{{cite web | title=eCFR :: 21 CFR 182.60 -- Synthetic flavoring substances and adjuvants. | website=eCFR | date=2021-10-27 | url=https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-182/subpart-A/section-182.60 | access-date=2021-10-29}}