Methyl allyl sulfides

Examination of 37 basidiomycetous yeasts indicated formation of several sulfur volatiles 3-(methylthio)-l-propanol, methanethiol (MT), S-methyl thio-acetate, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), allyl methyl sulfide and 4,5-dihydro-3(2//)-thiophenone. The component produced in the largest amounts, 40 100 mg L-1, was 3-(methylthio)-l-propanol29 Cheeseripening yeasts are considered later (Section 11.1.2.4.5). 

Recently, Germain et al. (90) studied the in vivo metabolism of diallyl disulfide (DADS), a garlic compound claimed to have anticarcinogenic effects. After oral administration of a single dose of 200mg/kg, metabolites were measured in the stomach, liver, plasma, and urine by GC coupled with MS over 15 days. DADS was detected in almost all analyzed tissues within the first hours. In addition, the metabolites allylmercaptan (AM) and allyl methyl sulfide (AMS) were detected. The Cmav of the metabolites were higher than that of DADS (1.46 pg/mL). The %ax for DADS was estimated to be less than one hour, whereas this time increased to 24 hours for AM and AMS (90). 

R Me Allyl methyl sulfide [12J, R AUyl Diillyl sulfide [8]... 

Indeed, all three expressions give essentially the same value for allyl methyl sulfide. 

Catalyst poisoning by sulfur has discouraged development of procedures for cleavage of sulfides. Desulfurization of highly activated allylic methyl sulfides can be effected by addition of lead to the palla-dium(O) catalyst. In the presence of various tertiary amines satisfactory cleavage of several related allyl sulfides has been utilized (equation 12) using a modified Pd/CaCOs catalyst. 

The hydroboration of heteroallyl derivatives often produces boron-heteroatom rings. These reactions are very closely related to the internal hydroborations discussed in Section 4.17.9.1.2. The hydroboration of 2-vinylpyrrole affords boron-nitrogen heterocycle 189 (Equation 29) <1997JOM181>. Two important hydroborations of allyl methyl sulfide <1971JA2823> and the allene 190 <1989JOC5814> are shown in Equations (30) and (31), respectively. The reduction/ hydroboration of 191 probably occurs via the intermediacy of 192 (Scheme 23) <1992JOC5288>. 

It can be seen that, under similar conditions, the reactivity of the dialkyl sulfides is directly linked to their molecular size Et2 S > Pr2 S > Bu2 S, and saturated sulfides are more reactive than allyl or aryl sulfides Pr2 S > Me S Allyl > Allyb S > Me S Ph > Ph2 S. These results can be explained, first, if we take into account the relative easiness of thioethers accessibility to the Ti active sites of the catalytic species located in the zeolite framework. The diffusion of the bulkier molecules, such as Ph2S is very difficult even inside the large pores of Ti-beta zeolite. Secondly, the reactivity of thioethers is in agreement with the nucleophilicity of the sulfur atom, so that alkyl sulfides are more easily oxidized than allyl or aryl sulfides by H2O2 (an electrophilic oxidant) in agreement with reported results [1-9]. It must be pointed out, that in the case of allyl methyl sulfide and di-allylsulfide, the epoxidation of the allyl system is not observed under our experimental conditions. 

Methyl vinyl sulfide Divinyl sulfide (Vinyl sulfide) Allyl methyl sulfide Diethyl sulfide (Ethyl sulfide)... 

Thermal desorption of purged and trapped garlic breath was studied by GC/MS [53] in which allyl methyl sulfide, diallyl sulfide, diallyl disulfide, -cymene and D-limonene were found consistently in all subjects, however, allyl thiol was detected occasionally. Preliminary evidence suggest that stomach acid caused increased evolution of hydrogen sulfide, a potential breath odor compound, during digestion. 

Among the main garlic-related compounds detected in the breath by GC-AED were allyl methyl sulfide, allyl metfiyl disulfide, diallyl sulfide, diallyl disulfide, 2-propenethiol, dimethyl disulfide, and diallyl trisulfide [54]. Measurements taken shortly after Ae ingestion of garlic and at four hourly intervals thereafter, indicating a more rapid decrease with time of diallyl disulfide than allyl methyl sulfide. Allyl methyl disulfide, diallyl sulfide, and diallyl trisulfide were reported to decrease slowly, while 2-propenethiol vanished rapidly. 

The breath of a test person was analyzed over a time period of about 30 hours by means of proton-transfer-reaction mass spectrometry [55]. After ingestion of cut raw garlic, tiie components allyl metfiyl sulfide, allyl methyl disulfide, diallyl sulfide, diallyl disulfide, diallyl trisulfide, dimethyl sulfide, and acetone were detected. While the concentrations of allyl mediyl disulfide, diallyl sulfide, diallyl disulfide, and diallyl trisulfide reached maximum concentration shortly after ingestion of garlic and declined to baseline values within the next 2-3 h, concentrations of allyl methyl sulfide, dimethyl sulfide, and acetone increased much more slowly... 

Three heterocyclic aromatic amines, 2-amino-3-methyl-imidazo[4, 5-f]quinoline (IQ),2-amino-3,4-dimethylimidazo[4,5-f]quinoxaline and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, have been found in boiled pork juice [109]. Six organosulfur compoimds - diallyl disulfide (DAD), dipropyl disulfide (DPD), diallyl sulftde (DAS), allyl methyl sulfide (AMS), allyl mercaptan (AM) and cysteine - were added separately to the pork juice before reflux boiling and then the mutagenicity of each sample was examined with the Salmonella typhimurium strain TA98 in the presence of S9 mix. All six compounds were found to inhibit the mutagenicity of boiled pork juice. The greatest inhibitory effect was observed with DAD and DPD, and this was 111-fold higher than that of... 

Allyl methyl sulfide, allyl mercaptan and methyl mercaptan were detected in the expired air of human subjects after the subjects chewed and ate 1000 mg of grated raw or grated heat-treated garlic for 30 s. Analytical concentrations of allyl methyl sulfide in raw garlic and heated garlic at 0 min were about 0.03 mg/kg and 0.005 mg/kg, respectively, and after 30 min had decreased to approximately 0.01 mg/kg and <0.005 mg/kg, respectively (Tamaki Sonoki, 1999). 

Allyl mercaptan and allyl methyl sulfide were identified as metabolites of diallyl disulfide when primary rat hepatocytes were incubated with either diallyl disulfide or diallyl sulfide. The highest identified concentration of allyl methyl sulfide (0.93 0.08 pg/ml at 90 min) was markedly lower than that of allyl mercaptan (46.2 6.6 pg/ml at 60 min). The results also showed that allyl methyl sulfide is a metabolite of diallyl sulfide (Sheen et al., 1999). 

We have found that metathesis of olefmic sulfides can be successfully achieved by using, as homogeneous catalyst, the aryloxy(chloro)neopentylidene-tungsten complex 1. Thus, the self-metathesis of allyl methyl sulfide (4) and of 5-dkylthiocycloooctenes (5) (or their cometathesis with various acyclic or cyclic olefins without functional groups) can lead to a family of new olefins, dienes, or unsaturated polymers containing one or more thioether groups. 

In the presence of 1, the self-metathesis of allyl methyl sulfide (4), or its co-metathesis with 2-butene (6a) or 2-pentene (6b), actually occurs and leads to the expected products (Scheme 6) [40]. 

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