Allyl-isothiocyanate

Amongst the more unusual reactions, 2,3-thiazolo fused pyrido[3,2-d]pyrimidines have been prepared from 3-aminopicolinic acid and 2-bromothiazoles, whilst a similar derivative resulted with allyl isothiocyanate (221 222) <72IJC602). Similar products are also produced in [3 + 3] reactions of 2-aminothiazoles (Section 2.15.5.7.1). 

Heating or irradiating alkenes in the presence of sulfur gives relatively low yields of thiiranes. For example, a mixture of sulfur and norbornadiene in pyridine-DMF-NHa at 110 °C gave a 19% yield of the monoepisulfide of norbornadiene as compared with a 78% yield by the method of Scheme 120 (79JCS(Pi)228). Often 1,2,3-trithiolanes are formed instead of thiiranes. The sesquiterpene episulfides in the essential oil of hops were prepared conveniently by irradiation of the terpene and sulfur in cyclohexane (Scheme 135) (80JCS(Pl)3li). Phenyl, methyl or allyl isothiocyanate may be used as a source of sulfur atoms instead of elemental sulfur. 

Allyl isothiocyanate, CHj CH. CH N C S, also known as artificial mustard oil, is the principal constituent of natural oil of mustard. This body results from the hydrolysis of the glucoside sinigrin under the influence of the ferment myrosin, according to the equation—... 

Allyl isothiocyanate is a colourless liquid, gradully becoming yellow on keeping, and having an intensely irritating odour of mustard. Its characters are as follows —... 

Volatile Inhibitors. Of the volatile components that influence plant growth and development, ethylene has received the most attention. Literature concerned with the variety of effects produced by ethylene, factors which influence its production, and the mechanisms through which responses are expressed has been reviewed by Evenari (57). Other gaseous excretions with inhibitory effects considered by Evenari include hydrogen cyanide, ammonia, essential oils, and mustard oils (probably allyl isothiocyanate and /3-phenethyI isothiocyanate). 

In a 5-I. round-bottomed flask, equipped with a reflux condenser connected to a gas trap (Note 1), are placed 2 1. (12.r moles) of 20 per cent hydrochloric acid and 500 g. (5.05 moles) of allyl isothiocyanate (Note 2). The mixture is refluxed over a free flame until the upper layer of allyl isothiocyanate has completely disappeared, about fifteen hours being required for the hydrolysis. When the reaction is complete, the solution is -poured into a 3-I. beaker and concentrated on the steam bath until crystals begin to form in the hot solution. This occurs when the volume is approximately 400 cc. (Note 3). 

It is desirable to use a gas trap in order to prevent vapors of allyl isothiocyanate from escaping into the room. The gas trap described in Org. Syn. Coll. Vol. 1, 91, is suitable. 

Eastman s practical grade (b. p. 150-152°) of allyl isothiocyanate was used in this preparation. 

Allylamine has been prepared from allyl isothiocyanate by hydrolysis with dilute sulfuric 1 or hydrochloric2 acid. 

ELFOUL L, RABOT s, KHELIFA N, QUINSAC A, DUGUAY A and RiMBAULT A (2001) Formation of allyl isothiocyanate from sinigrin in the digestive tract of rats monoassociated with a hiunan colonic strain of Bacteroides thetaiotaomicron , FEMS Microbiol Lett, 197 99-103. 

SMITH T, MUSK s R and JOHNSON I T (1996) Allyl isothiocyanate selectively kills undifferentiated HT29 cells in vitro and suppresses aberrant crypt foci in the colonic mucosa of rats , Biochem Soc Trans, 24 381S. 

Rubefacients Produce redness Allyl isothiocyanate 0.5-5% Ammonia water 1 -2.5% Musterole Extra Made by dilution of concentrated solution with water Mustard derivative Pungent odor Avoid inhalation More concentrated solutions are highly caustic Avoid inhalation... 

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. Exothermic polymerisation seems a likely possibility. 

An example of a larval parasitoid that responds to the host sex pheromone is seen with Cotesiaplutellae (Braconidae), also a parasitoid of the diamondback moth. These insects were attracted equally to the pheromone blend (31,32,33, see above), the acetate 32, or aldehyde 31 components [80]. This larval parasitoid, however, was also strongly attracted to host frass volatiles, in particular, dipropyl disulfide 34, dimethyl disulfide 35, allyl isothiocyanate 36, and dimethyl trisulfide 37. In contrast, the egg parasitoid Trichogramma chilonis was only weakly attracted to 36. In both, T. chilonis and C. plutellae, plant volatiles, in particular (3Z)-hex-3-en-l-yl acetate 38, significantly enhanced attraction by the pheromone [80]. 

Host frass volatiles [attraction] Dipropyl disulfide 34, dimethyl disulfide 35, allyl isothiocyanate 36 dimethyl trisulfide 37 [80]... 

Other assays have been used to evaluate the antioxidant activity against H202 of several plant-based products, namely, fruit juices from different cultivars of berries (Wang and Jiao 2000), fractions rich in phenolics isolated from the aqueous by-products obtained during the milling of oil palm fruits (Balasundram and others 2005), cherry laurel fruit and its concentrated juice (Liyana-Pathirana and others 2006), and strawberries and blackberries treated with methyl jasmonate, allyl isothiocyanate, essential oil of Melaleuca alternifolia, and ethanol (Chanjirakul and others 2007). 

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