Dimethyl trisulfide (DMTS) is an

organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

and the simplest organic trisulfide, with the chemical formula CH₃SSSCH₃. It is a flammable liquid with a foul odor, which is detectable at levels as low as 1 part per trillion.

Occurrence

Dimethyl trisulfide has been found in volatiles emitted from cooked onion, leek and other ''

Allium ''Allium'' is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. The generic name ''Allium'' is the Latin word for garlic,Gledhill, Davi ...

'' species, from broccoli and cabbage, as well as from

Limburger cheese Limburger (in southern Dutch contexts Rommedoe, and in Belgium Herve cheese) is a cheese that originated in the Herve area of the historical Duchy of Limburg, which had its capital in Limbourg-sur-Vesdre, now in the French-speaking Belgian Liè ...

, and is involved in the unpalatable aroma of aged beer and stale Japanese

sake Sake, also spelled saké ( ; also referred to as Japanese rice wine), is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name ''Japanese rice wine'', sake, and indee ...

. It is a decomposition product of bacterial decomposition, including the early stages of human decomposition, and is a major attractant for

blowflies The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing b ...

looking for hosts. Dimethyl trisulfide along with

dimethyl sulfide Dimethyl sulfide (DMS) or methylthiomethane is an organosulfur compound with the formula (CH3)2S. Dimethyl sulfide is a flammable liquid that boils at and has a characteristic disagreeable odor. It is a component of the smell produced from cook ...

and

dimethyl disulfide Dimethyl disulfide (DMDS) is an organic chemical compound with the molecular formula which is the simplest disulfide. It is a flammable liquid with an unpleasant, garlic-like odor. Occurrence Dimethyl disulfide is a widespread natural odorifero ...

have been confirmed as volatile compounds given off by the fly-attracting plant known as dead-horse arum ('' Helicodiceros muscivorus''). These flies are attracted to the

odor 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 caused by one or more volatilized chemical compounds ...

of fetid meat and help pollinate this plant. DMTS contributes to the foul odor given off by the fungus ''

Phallus impudicus ''Phallus impudicus'', known colloquially as the common stinkhorn, is a widespread fungus in the Phallaceae (stinkhorn) family. It is recognizable for its foul odor and its phallic shape when mature, the latter feature giving rise to several n ...

'', also known as the common stinkhorn. DMTS causes the characteristic malodorous smell of a

fungating lesion A fungating lesion is a skin lesion that fungates, that is, becomes like a fungus in its appearance or growth rate. It is marked by ulcerations (breaks on the skin or surface of an organ) and necrosis (death of living tissue) and usually presents ...

, e.g., from

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

wounds, and contributes to the odor of human feces. DMTS can be synthesized by the reaction of

methanethiol Methanethiol (also known as methyl mercaptan) is an organosulfur compound with the chemical formula . It is a colorless gas with a distinctive putrid smell. It is a natural substance found in the blood, brain and feces of animals (including hum ...

with

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...

(in the presence of copper (II)) and with

sulfur dichloride Sulfur dichloride is the chemical compound with the formula . This cherry-red liquid is the simplest sulfur chloride and one of the most common, and it is used as a precursor to organosulfur compounds. It is a highly corrosive and toxic substance, ...

, among other methods: :2 CH₃SH + SCl₂ → CH₃SSSCH₃ + 2 HCl

Chemical reactions

On heating at 80 °C, DMTS slowly decomposes to a mixture of dimethyl di-, tri-, and tetrasulfides. The reactivity of DMTS is related to its weak sulfur-sulfur bond (ca. 45 kcal/mol). Dimethyl tetrasulfide, which is thermally more reactive than dimethyl trisulfide, has a still weaker (central) sulfur-sulfur bond (ca. 36 kcal/mol). Oxidation of DMTS by

meta-chloroperoxybenzoic acid ''meta''-Chloroperoxybenzoic acid (mCPBA or ''m''CPBA) is a peroxycarboxylic acid. A white solid, it is used widely as an oxidant in organic synthesis. mCPBA is often preferred to other peroxy acids because of its relative ease of handling. mC ...

(mCPBA) gives the corresponding ''S''-monoxide, CH₃S(O)SSCH₃.

Uses

Trap baits containing dimethyl trisulfide have been used to capture '' Calliphora loewi'' and other blowflies. Dimethyl trisulfide has been found to be an effective cyanide antidote in a rodent model for

cyanide poisoning Cyanide poisoning is poisoning that results from exposure to any of a number of forms of cyanide. Early symptoms include headache, dizziness, fast heart rate, shortness of breath, and vomiting. This phase may then be followed by seizures, slow h ...

both against subcutaneous

potassium cyanide Potassium cyanide is a compound with the formula KCN. This colorless crystalline salt, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications includ ...

and inhaled

hydrogen cyanide Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an ...

, converting cyanide to much less toxic

thiocyanate Thiocyanate (also known as rhodanide) is the anion . It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) thiocyanate was formerly used in pyrot ...

. It is suggested that dimethyl trisulfide can be used in a mass casualty cyanide exposure setting. In conjunction with these studies, the LD₅₀ of dimethyl trisulfide in CD-1 mice was found to be 598.5 mg/kg, which may be compared to the LD₅₀ of

of 8.0 mg/kg.

References

{{sulfur compounds Organosulfur compounds Foul-smelling chemicals