Allyl isothiocyanate

{{chembox

|Verifiedfields = changed

|Watchedfields = changed

|verifiedrevid = 477314225

|Name = Allyl isothiocyanate

|ImageFile = Allyl-isothiocyanate-2D-skeletal.png

|ImageSize = 200px

|ImageName = Allyl isothiocyanate

|ImageFile1 = Allyl-isothiocyanate-3D-vdW.png

|ImageSize1 = 150px

|ImageName1 = Space-filling model of allyl isothiocyanate

|PIN = 3-Isothiocyanatoprop-1-ene

|OtherNames = Synthetic mustard oil

|Section1={{Chembox Identifiers

|IUPHAR_ligand = 2420

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

|UNII = BN34FX42G3

|ChEBI_Ref = {{ebicite|changed|EBI}}

|ChEBI = 73224

|KEGG_Ref = {{keggcite|correct|kegg}}

|KEGG = D02818

|KEGG1=C19317

|InChI = 1/C4H5NS/c1-2-3-5-4-6/h2H,1,3H2

|InChIKey = ZOJBYZNEUISWFT-UHFFFAOYAS

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

|StdInChI = 1S/C4H5NS/c1-2-3-5-4-6/h2H,1,3H2

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

|StdInChIKey = ZOJBYZNEUISWFT-UHFFFAOYSA-N

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

|CASNo = 57-06-7

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

|ChEMBL = 233248

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

|ChemSpiderID = 21105854

|SMILES = C=CCN=C=S

|PubChem = 5971

|EINECS = 200-309-2

|RTECS = NX8225000

|UNNumber = 1545

}}

|Section2={{Chembox Properties

|C=4|H=5|N=1|S=1

|Density = 1.013–1.020 g/cm³

|MeltingPtC = −102

|BoilingPtC = 148 to 154

}}

|Section7={{Chembox Hazards

|GHSPictograms = {{GHS02}}{{GHS06}}{{GHS07}}{{GHS09}}

|GHSSignalWord = Danger

|HPhrases = {{H-phrases|226|301|310|315|319|330|335|410}}

|PPhrases = {{P-phrases|210|233|240|241|242|243|260|261|262|264|270|271|273|280|284|301+310|302+350|302+352|303+361+353|304+340|305+351+338|310|312|320|321|322|330|332+313|337+313|361|362|363|370+378|391|403+233|403+235|405|501}}

}}

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.{{cite journal | last1 = Everaerts | first1 = W. | last2 = Gees | first2 = M. | last3 = Alpizar | first3 = Y. A. | last4 = Farre | first4 = R. | last5 = Leten | first5 = C. | last6 = Apetrei | first6 = A. | last7 = Dewachter | first7 = I. | last8 = van Leuven | first8 = F. | last9 = Vennekens | first9 = R.| title = The Capsaicin Receptor TRPV1 is a Crucial Mediator of the Noxious Effects of Mustard Oil | journal = Current Biology | year = 2011 | volume = 21 | issue = 4 | pages = 316–321 | pmid = 21315593 | doi = 10.1016/j.cub.2011.01.031 | s2cid = 13151479 | doi-access = free| bibcode = 2011CBio...21..316E | hdl = 2078.1/121650 | hdl-access = free }}{{cite journal |author1=Brône, B. |author2=Peeters, P. J. |author3=Marrannes, R. |author4=Mercken, M. |author5=Nuydens, R. |author6=Meert, T. |author7=Gijsen, H. J. | title = Tear gasses CN, CR, and CS are potent activators of the human TRPA1 receptor | journal = Toxicology and Applied Pharmacology | year = 2008 | volume = 231 | issue = 2 | pages = 150–156 | pmid = 18501939 | doi = 10.1016/j.taap.2008.04.005 |bibcode=2008ToxAP.231..150B }}{{cite journal |author1=Ryckmans, T. |author2=Aubdool, A. A. |author3=Bodkin, J. V. |author4=Cox, P. |author5=Brain, S. D. |author6=Dupont, T. |author7=Fairman, E. |author8=Hashizume, Y. |author9=Ishii, N. | title = Design and Pharmacological Evaluation of PF-4840154, a Non-Electrophilic Reference Agonist of the TrpA1 Channel | journal = Bioorganic & Medicinal Chemistry Letters | year = 2011 | volume = 21 | issue = 16 | pages = 4857–4859 | pmid = 21741838 | doi = 10.1016/j.bmcl.2011.06.035 |display-authors=etal}} It is slightly soluble in water, but more soluble in most organic solvents.{{Ullmann | author = Romanowski, F. |author2=Klenk, H. | title = Thiocyanates and Isothiocyanates, Organic | doi = 10.1002/14356007.a26_749}}

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.{{cite journal |doi=10.1016/j.phytochem.2019.112100 |doi-access=free |title=Glucosinolate structural diversity, identification, chemical synthesis and metabolism in plants |year=2020 |last1=Blažević |first1=Ivica |last2=Montaut |first2=Sabine |last3=Burčul |first3=Franko |last4=Olsen |first4=Carl Erik |last5=Burow |first5=Meike |last6=Rollin |first6=Patrick |last7=Agerbirk |first7=Niels |journal=Phytochemistry |volume=169 |page=112100 |pmid=31771793 |bibcode=2020PChem.169k2100B |s2cid=208318505 }} This serves the plant as a defense against herbivores; since it is harmful to the plant itself,{{Cite journal |last1=Li |first1=Yingbin |last2=Lu |first2=Daqing |last3=Xia |first3=Yan |last4=Xu |first4=Xinjing |last5=Huang |first5=Huichuan |last6=Mei |first6=Xinyue |last7=Yang |first7=Min |last8=Li |first8=Jianqiang |last9=Zhu |first9=Shusheng |last10=Liu |first10=Yixiang |last11=Zhang |first11=Zhiping |date=2023-09-30 |title=Effects of allyl isothiocyanate fumigation on medicinal plant root knot disease control, plant survival, and the soil bacterial community |journal=BMC Microbiology |volume=23 |issue=1 |pages=278 |doi=10.1186/s12866-023-02992-w |doi-access=free |issn=1471-2180 |pmc=10542678 |pmid=37775764 |quote=Allyl isothiocyanate (AITC) [...] has been used in agriculture because of its fungicidal [...] bactericidal, nematocidal [able to destroy nematodes], and herbicidal [able to destroy plants] biological activities. }} 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.{{Cite book |editor-last=Melton |editor-first=Laurence |title=The Encyclopedia of Food Chemistry |publisher=Elsevier |year=2019 |isbn=978-0-12-814045-1 |location=Netherlands }}{{rp|105}}

The compound has been shown to strongly repel fire ants (Solenopsis invicta).{{cite journal | doi = 10.1007/s13355-019-00613-5 | title = Wasabi versus red imported fire ants: Preliminary test of repellency of microencapsulated allyl isothiocyanate against Solenopsis invicta (Hymenoptera: Formicidae) using bait traps in Taiwan | date = 2019 | last1 = Hashimoto | first1 = Yoshiaki | last2 = Yoshimura | first2 = Masashi | last3 = Huang | first3 = Rong-Nan | journal = Applied Entomology and Zoology | volume = 54 | issue = 2 | pages = 193–196 | bibcode = 2019AppEZ..54..193H | url = https://oist.repo.nii.ac.jp/?action=repository_uri&item_id=1557 }} AITC vapor is also used as an antimicrobial and shelf life extender in food packaging.{{rp|118–120}}

Production and applications

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

:CH₂=CHCH₂Cl + KSCN → CH₂=CHCH₂NCS + KCl

The product obtained in this fashion is sometimes known as synthetic mustard oil.

Allyl thiocyanate isomerizes to the isothiocyanate:{{cite journal |doi=10.1021/ed048p81 |title=The Preparation and Isomerization of Allyl Thiocyanate. An Organic Chemistry Experiment |date=1971 |last1=Emergon |first1=David W. |journal=Journal of Chemical Education |volume=48 |issue=1 |page=81 |bibcode=1971JChEd..48...81E }}

:{{chem2|CH2\dCHCH2SCN -> CH2\dCHCH2NCS}}

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 US Patent No. 8691042 bacteriocide,{{cite journal |last1=Masuda |first1=Shuichi |last2=Masuda |first2=Hideki |last3=Shimamura |first3=Yuko |last4=Sugiyama |first4=Chitose |last5=Takabayashi |first5=Fumiyo |title=Improvement Effects of Wasabi (Wasabia japonica) Leaves and Allyl Isothiocyanate on Stomach Lesions of Mongolian Gerbils Infected with Helicobacter pylori |journal=Natural Product Communications |date=April 2017 |volume=12 |issue=4 |pages=595–598 |doi=10.1177/1934578X1701200431 |pmid=30520603|s2cid=54567566 |doi-access=free }} and nematicide, and is used in certain cases for crop protection. It is also used in fire alarms for the deaf.{{US patent reference|number= 20100308995A1|issue-date= 2015-06-24 |inventor= Hideaki Goto, Tomo Sakai, Koichiro Mizoguchi, Yukinobu Tajima, Makoto Imai| title= Odor generation alarm and method for informing unusual situation}}{{cite web |last1=Phillipson |first1=Tacye |title=Why would you want a wasabai fire alarm? |url=https://blog.nms.ac.uk/2018/08/29/why-would-you-want-a-wasbai-fire-alarm/ |website=National Museums Scotland Blog |date=29 August 2018 |access-date=10 March 2022}}

Hydrolysis of allyl isothiocyanate gives allylamine.{{OrgSynth | author = Leffler, M. T. | title = Allylamine | volume = 18 | pages = 5 | collvol = 2 | collvolpages = 24 | year = 1938 | prep = CV2P0024 }}

Safety

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

=Oncology=

Based on in vitro experiments and animal models, allyl isothiocyanate exhibits many of the desirable attributes of a cancer chemopreventive agent.{{Cite journal

| pmid = 19960458

| year = 2010

| last1 = Zhang

| first1 = Y

| title = Allyl isothiocyanate as a cancer chemopreventive phytochemical

| journal = Molecular Nutrition & Food Research

| volume = 54

| issue = 1

| pages = 127–35

| doi = 10.1002/mnfr.200900323

| pmc = 2814364

}}