Diallyl sulfide

Diallyl sulfide refers to the following 4 ingredients: diallyl monosulfide, diallyl disulfide, diallyl trisulfide and diallyl tetrasulfide, which exist in putrefaction decomposer of vegetables, green onion and the fruit of.cruciferous plants. As the main component of garlic extract, it is featured with strong anti-cancer, anti-virus, antibacterial activity, strong inhibition of platelet aggregation and immunity improvement. It has been widely used in the industries such as medical and health, fodder and the like.

It is an oily substance scented with garlic. Boiling point: 139 ° C (101.056Pa), relative density: 0.8876, refractive index: 1.4877. Soluble in organic solvents such as ether and the like, insoluble in water. Also it can be oxidized to diallyl sulfone.

Figure 1: Diallyl Disulfide

Figure 2: Diallyl trisulfide

The two main methods for preparation of diallyl sulfide are: biological extraction and chemical synthesis.

• Biological extraction

The more common biological extraction methods are steam distillation, organic solvent extraction and supercritical CO2 extraction. Steam distillation is to use water as a solvent, then heat under a certain pressure to extract the soluble active ingredients from the natural products. The advantage of this method is that it is simple to operate and suitable for the extraction of active ingredients that are generally easier to extract. Its disadvantages include the greater loss of the active ingredients in the thermosensitives, lower yield, and that the active ingredients in the extract are not easily separated.
Process for allicin extraction: fermentation temperature:  50 ~ 55 ℃, fermentation duration: 2h ~ 3h, add water into the garlic with the proportion of 1: 4 water, distilled for the duration of 1.5h ~ 2h.
Organic solvent extraction method is to use organic solvent as extraction agent, and extract the active ingredients of natural products at a certain temperature and extraction duration.  Usually methanol, ethanol, acetone, ethyl ether or the mixture of these solvents are used as the organic solvents. Compared withthe steam distillation extraction, the advantage of the organic solvent extraction is that the extract has higher purity. Also it is one of the traditional extraction methods.
Use ethanol with volume fraction of 95% as the extraction solvent, and add the extractant in proportion of 1g: 4mL. First the enzymolysis time was 0.5h when the temperature is set to 40 ℃; then have the extraction for 1.5h when the temperature is set to 30 ℃; finally set the temperature at 50 ℃, and have it concentrated under reduced pressure in a steamer rotating at a speed of 4500r / min to extract allicin. The extraction rate can reach 0.24%.

• Chemical synthesis

Mix Na2S2O3•5H2O62g (0.25mol) and 3-bromopropene 24g (0.20mol) in ethanol - water (V ethanol: V water = 60:40) evenly and reflux to homogeneity. Add 30mL of concentrated hydrochloric acid, reflux for 5h, standing still, then separate the upper layer and put it into 100mL10% NaOH solution placed in an ice bath, add 80mL of 25% K3Fe (CN) 6 (6mmol) aqueous solution while stirring and stop after 2.5h. Separate the organic layer and dry it over anhydrous sodium sulfate. Then filter off the desiccant, recover the solvent, and finally 6.6 g of pale yellow oily substance will be obtained. 
Figure 3： Synthetic route

Used as a reagent. 
Used in the industries such as medical and health, fodder and the like.

GRAS(FEMA)。

FEMA (mg / kg): Drinks 0.04; Cold Drink 0.06; Confectionery 0.07; Bakery Products 0.05; Seasoning 13; Meat 3.7.
FDA, § 172.515: Appropriate amount.

A colorless liquid with characteristic garlic odor. Oil-soluble component of garlic

clear colorless liquid

Reported found in garlic (Allium sativum L.), onion (Allium cepa L.), nira (Allium tuberosum Rottl.), caucas (Allium victoralis L.), mustard (Brassica species) and cooked/boiled beef

antibacterial, antifungal, antineoplastic, antihypercholesterolaemic, hepatoprotectant

manufacture of flavors.

Diallyl sulfide is a modulator of drug metabolizing enzyme P450 system and inducer of the phase II detoxifying enzyme GST. Diallyl sulfide is also an inhibitor of CYP2E1 and believed to prevent chemically-induced carcinogenesis in many tissues. It is also used as a food additive. It is also used as an important raw material and intermediate used in organic Synthesis, pharmaceuticals, agrochemicals and dyestuff.

ChEBI: Diallyl sulfide is an organic sulfide.

From allyl iodide plus potassium sulfide in alcoho

Detection at 0.05 ppb

Taste characteristics at 2 ppm: sulfureous, onion–garlic and vegetative radish-like with a slightly hot nuance

Allyl sulfide is a volatile flavor compound naturally found in Allium species such as garlic and onion. It is has a characteristic garlic odor and is used as a flavoring agent in meat and condiments.

Organosulfur compound from garlic that inhibits chemically-induced carcinogenesis in experimental animals. Competitive inhibitor of Cytochrome P450 2E1 (CYP2E1) that, in turn, blocks the activation of several chemcal carcinogens.

It is a thioether, found in garlic, inhibits cytochrome P450 IIE1 isoform, and therebysuppresses carcinogenesis (Aggarwal and Shishodia 2004). The consumption ofgarlic provides protection from gastrointestinal cancers and also suppresses theprogression of colorectal adenomas (Hosseini and Ghorbani 2015).