Diallyl disulfide (DADS or 4,5-dithia-1,7-octadiene) is an organosulfur compound derived from garlic and a few other genus Allium plants. Along with diallyl trisulfide and diallyl tetrasulfide, it is one of the principal components of the distilled oil of garlic. It is a yellowish liquid which is insoluble in water and has a strong garlic odor. It is produced during the decomposition of allicin, which is released upon crushing garlic and other plants of the Alliaceae family. Diallyl disulfide has many of the health benefits of garlic, but it is also an allergen causing garlic allergy. Highly diluted, it is used as a flavoring in food. It decomposes in the human body into other compounds such as allyl methyl sulfide.
In the presence of iron chloride or copper chloride catalyst, or of liquid sulfur at 120 °ree;C Diallyl disulfide can be used as a precursor for the synthesis of higher diallyl polysulfides (polysulfanes). In agriculture, diallyl disulfide and related diallyl polysulfides show useful activity as environmentally-benign nematicides. Diallyl disulfide is also a starting material for the synthesis of allicin. In the food industry, diallyl disulfide is used to improve the taste of meat, vegetables and fruits.
Diallyl disulfide is an efficient agent for detoxication of the cells. It significantly increases the production of the enzyme glutathione S-transferase (GST), which binds electrophilic toxins in the cell. The release of organosulfur compounds upon destruction of Alliaceae plant cells has great importance, because of the antimicrobial, insecticidal and larvicidal properties of those compounds.
Garlic can prevent the colorectal cancer, and several studies revealed that diallyl disulfide is a major component responsible for this action. The effect is dose dependent as demonstrated on mice. Diallyl disulfide affects cancer cells much stronger than normal cells. It also results in a strong and dose-dependent accumulation of several agents, such as reactive oxygen species, which activate enzyme and lead to destruction of cancer cells.
There is evidence that garlic may prevent the development of cardiovascular diseases. A possible reason for some of these diseases, such as atherosclerosis or coronary heart disease is oxidative stress. The latter is reduced by diallyl disulfide by assisting in the detoxification of the cell, as well as some other mechanisms. By activating the TRPA1 ion channel, diallyl disulfide leads to a short-term lowering of blood pressure.
