Allyl isothiocyanate (AITC) is a naturally occurring unsaturated isothiocyanate. The colorless oil is responsible for the pungent taste of cruciferous vegetables such as mustard, radish, horseradish, and wasabi. This pungency and the lachrymatory effect of AITC are mediated through the TRPA1 and TRPV1 ion channels.[1][2][3] It is slightly soluble in water, but more soluble in most organic solvents.[4]

Allyl isothiocyanate
Allyl isothiocyanate
Space-filling model of allyl isothiocyanate
Preferred IUPAC name
Other names
Synthetic mustard oil
3D model (JSmol)
ECHA InfoCard 100.000.281 Edit this at Wikidata
EC Number
  • 200-309-2
RTECS number
  • NX8225000
UN number 1545
  • InChI=1S/C4H5NS/c1-2-3-5-4-6/h2H,1,3H2 checkY
  • InChI=1/C4H5NS/c1-2-3-5-4-6/h2H,1,3H2
  • C=CCN=C=S
Molar mass 99.15 g·mol−1
Density 1.013–1.020 g/cm3
Melting point −102 °C (−152 °F; 171 K)
Boiling point 148 to 154 °C (298 to 309 °F; 421 to 427 K)
GHS labelling:
GHS02: FlammableGHS06: ToxicGHS07: Exclamation markGHS09: Environmental hazard
H226, H301, H310, H315, H319, H330, H335, H410
P210, P233, P240, P241, P242, P243, P260, P261, P262, P264, P270, P271, P273, P280, P284, P301+P310, P302+P350, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P320, P321, P322, P330, P332+P313, P337+P313, P361, P362, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Biosynthesis and biological functions


Allyl isothiocyanate can be obtained from the seeds of black mustard (Rhamphospermum nigrum) or brown Indian mustard (Brassica juncea). When these mustard seeds are broken, the enzyme myrosinase is released and acts on a glucosinolate known as sinigrin to give allyl isothiocyanate.[5] This serves the plant as a defense against herbivores; since it is harmful to the plant itself,[citation needed] it is stored in the harmless form of the glucosinolate, separate from the myrosinase enzyme. When an animal chews the plant, the allyl isothiocyanate is released, repelling the animal. Human appreciation of the pungency is learned.[6]: 105 

The compound has been shown to strongly repel fire ants (Solenopsis invicta).[7] AITC vapor is also used as an antimicrobial and shelf life extender in food packaging.[6]: 118–120 

Production and applications


Allyl isothiocyanate is produced commercially by the reaction of allyl chloride and potassium thiocyanate:[4]


The product obtained in this fashion is sometimes known as synthetic mustard oil. Allyl thiocyanate isomerizes to the isothiocyanate:[8]


Allyl isothiocyanate can also be liberated by dry distillation of the seeds. The product obtained in this fashion is known as volatile oil of mustard.

It is used principally as a flavoring agent in foods. Synthetic allyl isothiocyanate is used as an insecticide, as an anti-mold agent [9] bacteriocide,[10] and nematicide, and is used in certain cases for crop protection.[4] It is also used in fire alarms for the deaf.[11][12]

Hydrolysis of allyl isothiocyanate gives allylamine.[13]



Allyl isothiocyanate has an LD50 of 151 mg/kg and is a lachrymator (similar to tear gas or mace).[4]



Based on in vitro experiments and animal models, allyl isothiocyanate exhibits many of the desirable attributes of a cancer chemopreventive agent.[14]

See also



  1. ^ Everaerts, W.; Gees, M.; Alpizar, Y. A.; Farre, R.; Leten, C.; Apetrei, A.; Dewachter, I.; van Leuven, F.; Vennekens, R. (2011). "The Capsaicin Receptor TRPV1 is a Crucial Mediator of the Noxious Effects of Mustard Oil". Current Biology. 21 (4): 316–321. Bibcode:2011CBio...21..316E. doi:10.1016/j.cub.2011.01.031. PMID 21315593. S2CID 13151479.
  2. ^ Brône, B.; Peeters, P. J.; Marrannes, R.; Mercken, M.; Nuydens, R.; Meert, T.; Gijsen, H. J. (2008). "Tear gasses CN, CR, and CS are potent activators of the human TRPA1 receptor". Toxicology and Applied Pharmacology. 231 (2): 150–156. doi:10.1016/j.taap.2008.04.005. PMID 18501939.
  3. ^ Ryckmans, T.; Aubdool, A. A.; Bodkin, J. V.; Cox, P.; Brain, S. D.; Dupont, T.; Fairman, E.; Hashizume, Y.; Ishii, N.; et al. (2011). "Design and Pharmacological Evaluation of PF-4840154, a Non-Electrophilic Reference Agonist of the TrpA1 Channel". Bioorganic & Medicinal Chemistry Letters. 21 (16): 4857–4859. doi:10.1016/j.bmcl.2011.06.035. PMID 21741838.
  4. ^ a b c d Romanowski, F.; Klenk, H. "Thiocyanates and Isothiocyanates, Organic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_749. ISBN 978-3527306732.
  5. ^ Blažević, Ivica; Montaut, Sabine; Burčul, Franko; Olsen, Carl Erik; Burow, Meike; Rollin, Patrick; Agerbirk, Niels (2020). "Glucosinolate structural diversity, identification, chemical synthesis and metabolism in plants". Phytochemistry. 169: 112100. Bibcode:2020PChem.169k2100B. doi:10.1016/j.phytochem.2019.112100. PMID 31771793. S2CID 208318505.
  6. ^ a b Melton, Laurence, ed. (2019). The Encyclopedia of Food Chemistry. Netherlands: Elsevier. ISBN 978-0-12-814045-1.
  7. ^ Hashimoto, Yoshiaki; Yoshimura, Masashi; Huang, Rong-Nan (2019). "Wasabi versus red imported fire ants: Preliminary test of repellency of microencapsulated allyl isothiocyanate against Solenopsis invicta (Hymenoptera: Formicidae) using bait traps in Taiwan". Applied Entomology and Zoology. 54 (2): 193–196. Bibcode:2019AppEZ..54..193H. doi:10.1007/s13355-019-00613-5.
  8. ^ Emergon, David W. (1971). "The Preparation and Isomerization of Allyl Thiocyanate. An Organic Chemistry Experiment". Journal of Chemical Education. 48 (1): 81. Bibcode:1971JChEd..48...81E. doi:10.1021/ed048p81.
  9. ^ US Patent No. 8691042
  10. ^ Masuda, Shuichi; Masuda, Hideki; Shimamura, Yuko; Sugiyama, Chitose; Takabayashi, Fumiyo (April 2017). "Improvement Effects of Wasabi (Wasabia japonica) Leaves and Allyl Isothiocyanate on Stomach Lesions of Mongolian Gerbils Infected with Helicobacter pylori". Natural Product Communications. 12 (4): 595–598. doi:10.1177/1934578X1701200431. PMID 30520603. S2CID 54567566.
  11. ^ US patent 20100308995A1, Hideaki Goto, Tomo Sakai, Koichiro Mizoguchi, Yukinobu Tajima, Makoto Imai, "Odor generation alarm and method for informing unusual situation", issued 2015-06-24 
  12. ^ Phillipson, Tacye (29 August 2018). "Why would you want a wasabai fire alarm?". National Museums Scotland Blog. Retrieved 10 March 2022.
  13. ^ Leffler, M. T. (1938). "Allylamine". Organic Syntheses. 18: 5; Collected Volumes, vol. 2, p. 24.
  14. ^ Zhang, Y (2010). "Allyl isothiocyanate as a cancer chemopreventive phytochemical". Molecular Nutrition & Food Research. 54 (1): 127–35. doi:10.1002/mnfr.200900323. PMC 2814364. PMID 19960458.