Allyl isothiocyanate

Chemical properties

Allyl Isothiocyanate is the main component of mustard oil (>95%). It is a highly flammable, colorless to pale yellow, oily liquid with a typical mustard odor. Exposure to air might cause it to darken. It has a pungent, irritating smell and a bitter taste that can cause lacrimatory. It can be synthesized by reacting allyl chloride with alkaline-earth or alkali rhodanides.

Occurrence

In the essential oil from seeds of Brassica nigra Koch, Brassica juncea Hook. and Thoms., and Thlaspi arvense; in the essential oil from roots of Cochlearia armoracia; in the seeds and roots of Alliaria officinalis; in onion juice; and in the seeds of various Cruciferae. Reported found in pineapple (Anans comoscus), raw cabbage, cooked cabbage, sauerkraut, milk, heated beans, horseradish (Armoracia lapathifolia), raw cauliflower, Brussels sprouts, turnip, Chinese cabbage, wasabi (Japanese horseradish) (Wasabi japonica).

The Uses of Allyl isothiocyanate

Allyl Isothiocyanate is a synthetic flavoring agent that is a moder- ately stable, colorless to pale yellow liquid of pungent and irritating odor. it should be stored in glass containers. it is used as an artificial oil of mustard and as an imitation horseradish flavor with applica- tion in condiments, meats, and pickles at 87 ppm. it is also termed mustard oil.

What are the applications of Application

Allyl isothiocyanate is a compound which induces phase II detoxification enzymes in urinary bladder

Preparation

By distillation of sodium thiocyanate and allyl chloride

Definition

ChEBI: Allyl isothiocyanate is an isothiocyanate with the formula CH2=CHCH2N=C=S. A colorless oil with boiling point 152℃, it is responsible for the pungent taste of mustard, horseradish, and wasabi. It has a role as a lachrymator, a metabolite, an antimicrobial agent, an apoptosis inducer and an antineoplastic agent. It is an isothiocyanate and an alkenyl isothiocyanate.

Production Methods

Producted from Allyl iodide and Potassium sulfocyanide. Allyl isothiocyanate is the chief component of the volatile oil of black Mustard seed, and can be isolated by enzymatic breakdown of the glycoside in the seed.

Synthesis Reference(s)

Tetrahedron Letters, 32, p. 3503, 1991 DOI: 10.1016/0040-4039(91)80817-P

General Description

A colorless to pale-yellow oily liquid with an irritating odor. Flash point 135°F. Boiling point 300°F. Poisonous by ingestion and skin absorption. Emits toxic fumes when heated to high temperature. Insoluble in water and slightly denser than water. Hence sinks in water. Used to make other chemicals and as a fumigant. It should be stored in glass containers.

Air & Water Reactions

Flammable. Insoluble in water.

Reactivity Profile

A routine preparation by interaction of allyl chloride and sodium thiocyanate in an autoclave at 5.5 bar exploded violently at the end of the reaction. Peroxides were not present or involved and no other cause could be found, but extensive decomposition occurred when allyl isothiocyanate was heated to 250°C. in glass ampoules [Ind. Eng. Chem. 1941:19 1408].

Hazard

Extremely penetrating, pungent and stinging odor. This chemical is a powerful Iachrymator, and inhalation of its vapors may cause serious damage to human lungs. The liquid and its vapors produce blisters on the human skin. A few grams may kill a man, if the oil is taken internally.

Health Hazard

TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Bromoacetates and chloroacetates are extremely irritating/lachrymators. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

Contact allergens

Allyl isothiocyanate is generated by enzymatic hydrolysis of the glucoside sinigrin, present in Cruciferae- Brassicaceae, mainly the oil from black mustard seed (Brassica nigra Koch). It may induce irritant and sometimes allergic contact dermatitis, mimicking the “tulip finger” dermatitis.

Anticancer Research

This compound was tested on Ehrlich ascites tumor cells transplanted in Swissalbino mice using HEK293 cells as control. There was a significantly reduced ascitessecretion and tumor cell proliferation. Also the vascular endothelial growth factorexpression was inhibited. The apoptosis was induced in tumor cells, and cellcycle was arrested at G1 phase (Ichwan et al. 2014).

Safety Profile

Suspected carcinogen with experimental neoplastigenic and tumorigenic data. Poison by ingestion, skin contact, intravenous, subcutaneous, and intraperitoneal routes. Experimental teratogenic and reproductive effects. An eye irritant. An allergen. May cause contact dermatitis. Mutation data reported. A flammable liquid. Highly reactive. When heated to decomposition (above 250') or on contact with acid or acid fumes it emits highly toxic fumes of CN-, SO,, and NOx. To fight fire, use foam, CO2, dry chemical. See also ALLYL COMPOUNDS and ESTERS.

Potential Exposure

Used in fumigants, veterinary drugs, ointments and counter irritants, mustard plasters, and as a flavoring agent.

Shipping

UN1545 Allyl isothiocyanate, stabilized, Hazard class: 6.1; Labels: 6.1-Poison Inhalation Hazard, 3 flammable liquids.

Purification Methods

Fractionate the isothiocyanate using an efficient column, preferably in a vacuum. It is a yellow pungent, irritating and TOXIC (suspected CARCINOGEN) liquid. Store it in a sealed tube under N2. The N'-benzylthiourea derivative has m 94.5o (from aqueous EtOH) [Weller et al. J Am Chem Soc 74 1104 1952]. [Beilstein 4 IV 1081.]

Incompatibilities

Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides, alcohols, amines