Methylthio propionic acid

The substances in this group that have been evaluated at this meeting and at the fifty-third and sixty-first meetings are predicted to be metabolized by a variety of metabolic pathways. Because of the diverse structures, there are few common metabolites. Examples are 3-(methylthio)propionic acid (from Nos 476 and 468) and thioacetic acid (from Nos 482, 483, 485 and 491). The combined intakes of substances with a common metabolite were below the relevant threshold of toxicological concern (TTC) value. 

S-Me 3-Methylmercaptopropanoic acid. 3-Methylthio-propionic acid. Methylthiohydracrylic acid. Bpos 102-104 . 

Nucleophilic replacement reactions (by AcS, Ph CO S , MeS , and PhCHaS") with methyl 0-toluene-p-sulphonyl-L-lactate and sodium L-2-chloropropionate give 2-acylthio- and 2-alkylthio-D-propionic acids and esters. Extensive racemization accompanies the use of excess thio-acetate or thiobenzoate, due to further 5 2 replacement reactions, as observed for LiAlH4 reduction of L-(2-methylthio)propionic acid or its methyl ester. Diborane reduction gives optically pure L-(2-methylthio)-propanol, however. This work includes a new synthesis of ( + )-2-mercaptopropionic acid, though by known methods, and establishes the D configuration for this isomer. 

A vinylsilane is a useful equivalent of ethylene, adducts with a sulphenyl chloride readily undergoing elimination. Another novel elimination approach, i.e. oxidative decarboxylation of 2-substituted 2-(methylthio)propionic acids, is brought about by treatment of the sodium salt of the acid with A-chlorosuccinimide. 

Ben2yloxyindolyl-3)-Q -acetvlamino-Q -methylthiopropionic acid methanethiol ester (449 mg) was added to 10 ml of ethanol and further 1 ml of triethylamine was added to the mixture. Then, the reaction mixture was refluxed for 17 hours, after condensation under reduced pressure and subsequent separation of the residue by column chromatography (silica gel, ethyl acetate), 353 mg of methyl -(5-benzyloxyindolyl-3)-Q -acetylamino-Q -methylthio-propionate was obtained as colorless glasslike substance in the yield of 81.5%. Recrystallization of the substance from methanol water afforded 287 mg of crystals. 

In addition methylthio substituted carboxylic acids are still unnoticed riverine contaminants. Methylthioacetic acid ethylester is a known volatile constituent of melones, passion fruits, further tropical fruits as well as wine (e.g. Wong and Ong, 1993, Beaulieu and Grimm 2001, Jordan et al. 2002, Moreira et al. 2002). Therefore its application as flavour constituent in fragrances seemed to be possible. Further technical usage also of methylthio acetic and propionic acids are unknown. On the contrary methylthiobenzothiazol and its metabolite benzothiazole are well known riverine contaminants as the result of their usage as biocorrosion inhibitors,... 

See Methyl ethyl sulfide 0-Ethyl-0-(4-(methylthio) phenyl) phosporodithioic acid-S-propyl ester 0-Ethyl-0-(4-(methylthio) phenyl) S-propyl phosphorodithioate. See Sulprofos Ethyl 3-(methylthio) propionate CAS 13327-56-5 EINECS/ELINCS 236-370-7... 

Propionaldehyde, p-(4-t-butylphenyl)-a-methyl-. See 4-t-Butyl-a-methylhydrocinnamaldehyde Propionaldehyde, 2,3-dibromo-. See 2,3-Dibromopropionaldehyde Propionaldehyde, 2-methyl-2-(methylthio)-, O-(methylcarbamoyl) oxime. SeeAldicarb Propionaldehyde, 2-methyl-2-(methylthio)-, oxime. See Aldicarb oxime Propionaldehyde, 3-(methylthio)-. See3-Methylthiopropionaldehyde Propionamide, N,N-diethyl-2-(1-naphthyloxy)-. See Napropamide Propione. See Diethyl ketone Propionic acid... 

An important sulfide is methional (8-37). Methional in beer and wine is formed by the activity of microorganisms. It is partly reduced to the corresponding alcohol methionol (8-13) and reaction with acetyl-CoA yields 3-methylthiopropyl acetate (8-129), which is an important component of various fermented foods. Another ester of acetic acid 3-(methylthio)hexyl acetate is a component that posseses attractive tropical fruity notes on dilution. The less odoriferous (-)-(J )-enantiomer (8-130) is reminiscent of passion fruit, while the (-l-)-(S)-form has a more herbaceous odour. The odour thresholds of these thiols in air are 0.10 ng/1 and 0.03 ng/1, respectively. Both isomers have been found in passion fruit (Passiflora edulis, Passifloraceae), guava Psidium guajava, Myrtaceae) and aromatic white wines. Methyl-3-(methylthio)propionate, or pineapple mercaptan (8-131), has a flavour reminiscent of pineapple. S-Methylthiohexanoate (8-132) is a component of the durian fruit smell. Condensation of methional with ethanol yields (Z)-2-(methylthio)methylbut-2-enal also known as 2-ethylidenemethional (8-133), which is an important component of potato chips aroma. It also occurs in... 

Propanoic acid, 3-(methylthio)-, methyl ester methyl 3-methylthiopropionate 122-63-4 Propanoic acid, phenylmethyl ester benzyl propionate ... 

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