Methyl mercaptan Methionine

The chloride is used to manufacture silicones, tetramethyl lead and triptane (2,2,3 trimethylbutane). Lesser uses include the manufacture of butyl rubber, higher halogenated methanes, methyl cellulose, quaternary ammonium compounds, methyl mercaptan, methionine, fungicides and pesticides (primarily the Me-arsenate herbicides). Recently the chlorinated fluorocarbons have replaced CH3CI as high volume refrigerants and propellants (ref. 32) Tables 12 and 13 list the chemical and physical properties and potential numbers of workers exposed to the monohalomethanes. 

The significance of industrial acrolein production may be clearer if one considers the two major uses of acrolein—direct oxidation to acryUc acid and reaction to produce methionine via 3-methyhnercaptopropionaldehyde. In acryUc acid production, acrolein is not isolated from the intermediate production stream. The 1990 acryUc acid production demand in the United States alone accounted for more than 450,000 t/yr (28), with worldwide capacity approaching 1,470,000 t/yr (29). Approximately 0.75 kg of acrolein is required to produce one kilogram of acryUc acid. The methionine production process involves the reaction of acrolein with methyl mercaptan. Worldwide methionine production was estimated at about 170,000 t/yr in 1990 (30). (See Acrylic ACID AND DERIVATIVES AmINO ACIDS, SURVEY.)... 

Hydroxy-4-methylthiobutyric acid [583-91 -5] the hydroxy analogue of the amino acid methionine, is manufactured by acid hydrolysis of 3-methylthiopropionaldehyde cyanohydrin [17773-41-0] which is produced by the reaction of methyl mercaptan with acrolein (qv). 

Methyl isovalerate, azeotropic mixtures with butyl alcohols, 4 395t Methyl ketones, acetic anhydride used in synthesis, 1 148 Methyllithium, 14 249 15 147 Methylmagnesium chloride, 16 319 (R)-(—)-Methylmandelic acid chloride, chiral derivatizing reagent, 6 76t Methyl mercaptan production, 15 17 3-Methylmercaptopropionaldehyde (MMP), intermediate in methionine synthesis, 1 268, 269, 276... 

Methionine Methyl mercaptan (s) Dimethyl sulfide (m) Dimethyl disulfide (1)... 

In 1949, C. J. Watson (W6) reported that methionine was peculiarly toxic in liver failure. Sherlock (S5) reported similar findings, and these observations led Challenger and Walshe (C3) to search for volatile thiols in the breath of patients with fetor hepaticus. The toxicity of mercaptans, presumably derived from methionine and cystine, was proposed as the cause of coma, and it was demonstrated that the breath of patients with fetor hepaticus contained methyl mercaptan. This observation, coupled with the finding of increased thiol levels in the blood of patients with hepatic disease, and a decreased ability to utilize cysteine (W4) gave some support to the proposal. The report that methionine... 

Methionine. Methionine is an essential amino acid that is used in animal feed. The key ingredients are HCN or NaCN, methyl mercaptan, acrolein and NH4HCO3. In 2003 global capacity was 450,000 to 500,000 tonnes per year. 

Why does eating asparagus produce bad-smelling urine Asparagus contains the amino acid methionine, which is metabolized in the body to produce methyl mercaptan. The peculiar odor of urine produced after consuming asparagus is caused by the methyl mercaptan excreted from the body in urine. 

Carbon monoxide Hydrogen Methane gas methionine synthesis Methyl mercaptan methoxycarbonylating agent Dimethyl dicarbonate methyl alcohol mfg. 

Mercaptide Elimination. Kallio and Larson have described an oxidative degradation of methionine by a Pseudomonas. A pyridoxal phosphate enzyme eliminates methyl mercaptan and ammonia, leaving a-ketobutyrate. The methyl mercaptide is oxidized to dimethyl disulfide. 

A cell free extract which contained 720 mg protein was mixed with C labeled methyl-mercaptan of specific activity 2.4 x 10 CPM/m mole. O-acetyl homoserine was also added. The total volume of the system did not exceed 1.5 ml. Since the cell-free extract was from a microorganism, it contained en mes required for methionine biosynthesis. Aliquots were drawn and fractionated for L-methlonine at different intervals. It could be determined that the rate of incorporation of radioactivity in methionine was 2240 CPM/min. Calculate the rate of en nnatlc reaction. 

Some volatile sulfur compounds were obtained from methionine and riboflavin after light irradiation under acidic conditions (Table I). Methyl mercaptan seems to be one of the important off-odor components. At this time, because of using the solvent extraction with dichloromethane, the amount of highly volatile methyl mercaptan seemed to be low. Therefore, we focused the other off-odor components, that is, methional, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and methyl methanethiosulfonate (MMTS). In particular, DMTS is considered to be significant because of its extremely low threshold value. Figure 1 shows that the amount of DMDS and DMTS increased with decreasing pH value. 

It thus appears that in animals d-methionine as well as Z-methionine can furnish the corresponding keto acid by oxidative deamination. But it is actually impossible to state there exists a relationship between the similarity in behavior of the two stereoisomers and the similarity of their ability to form sulfate. The fate of sulfur of the a-keto- v-methiobutyric acid is little known as yet according to Waelsch and Borek (140) the acid is broken down in acid or alkaline medium or by boiling to methyl mercaptan and an undetermined residue, and the authors think that this possibly represents a model of a physiological reaction. On the other hand, this same acid seems to be able to take part in the same transmethylation reactions as Z-methionine (58). It is therefore very unlikely that the sulfur of this keto acid can be oxidized directly to sulfate. 

Thiazolium, 3-methyl-2-((1-methyl-2-phenyl-1H-indol-3-yl) azo)-, chloride. See Basic red 29 2-Thiazolylamine. See 2-Aminothiazole, 2-(4-Thiazolyl) benzimidazole 2-(Thiazdl-4-yl) benzimidazole. See Thiabendazole 2-Thiazylamine. See 2-Aminothiazole Thieno (3,4-b)-1,4-dioxin, 2,3-dihydro. See 3,4-Ethylene dioxythiophene N-(2-Thienylcarbonyl)-L-methionine. See Thenoyl methionate 2-Thienyl mercaptan CAS 7774-74-5 FEMA 3062... 

Measurement of Antioxidative Activity. The antioxidative activity of the Maillard reaction products was evaluated by a method similar to that developed by Macku and Shibamoto (9) and later modified by Eiserich et al. 10). The antioxidative activities of 25 iiL-aliquots of peanut oil/cysteine and peanut oil/methionine dichloromethane extracts and 5 nL-aliquots of the glucose/cysteine extracts were measured. 2-Alkyl-thiophenes, 2-thiophenethiol, 2-methyl-3-furanthiol, fiirfuryl mercaptan, thiazolidine, and 1,3-dithiolane were tested for antioxidative activity at a concentration of 1 mM. The above extracts and standards were added to dichloromethane solutions containing 25 mg of heptanal. Nonadecane (400 mg) was added as a gas chromatographic internal standard, and the resulting solutions were brought to a 5-mL final volume with... 

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