4-Mercapto-4-methyl-2-pentanone

An example for stimulus generalization are responses of rats to stress-inducing odors. Laboratoiy rats of the Wistar strain respond to predator odors, specifically mercapto compounds in fox droppings, with stress reactions, for example avoidance behavior such as freezing and increased plasma corticosterone concentrations (Vemet-Mauiy et ah, 1984). The rats were trained to avoid water scented with a mercapto odorant that contained both a keto- and a sulfhydryl group (4-mercapto-4-methyl-2-pentanone). As the animals licked a waterspout, a mild electric shock was applied to their tongue. When different compounds were tested thereafter, the rats avoided compounds with similar... 

At a silver reclamation facility in Duval County, Florida, a Biocube bioflltration system used to treat vapors containing mercaptans (mainly 4-mercapto-4-methyl-2-pentanone) cost 18,000 (D13551D). 

Biocube (T0039) is a commercially available off-gas treatment system. A Biocnbe was installed at a domestic wastewater pumping facility in June 1995 at a cost of 15,000. The pumping facility treats approximately 200 m of water per day (50,000 gal per day) (D13550C, pp. 1-4). At a silver reclamation facility in Duval County, Florida, a Biocube biofiltration system used to treat vapors containing mercaptans (mainly 4-mercapto-4-methyl-2-pentanone) cost 18,000 (D13551D). 

Mercapto-4-methyl-2-pentanone CH3C(SHXCH3)CH2COCH3... 

As for the potent odorants in green tea (sen-cha) drinks, the eleven components shown in hgure 17.7 are found to be important contributors to its characteristics. Using the AEDA method, the characteristic sulfur components, such as 4-methoxy-2-methyl-2-butanethiol, 4-mercapto-4-methyl-2-pentanone, and methional, were identihed from the green tea for the first time. Among these eleven components, P-damascenone and methional were reported to increase after the heating process (hgure 17.4), then theorized to have a remarkable effect on the tea drink quality. 

Acetyl-1-pyrroline 4-Mercapto-4-methyl-2-pentanone 2-Ethyl-3,5-dimethylpyrazine (Popcorn-like) (Meaty) (Nutty)... 

FIGURE 17.16 Proposed precursor flavor components of 2-acetyl-l-pyrroline, 4-mercapto-4-methyl-2-pentanone, 2-acetyl-l-thiazoline, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone. 

Kumazawa, K., Kubota, K., and Masuda, H. 2005. Influence of manufacturing conditions and crop season on the formation of 4-mercapto-4-methyl-2-pentanone in Japanese green tea (sen-cha). J. Agric. Food Chem. 53 5390-96. 

However, the addition occurs contrary to the Markovnikov rule under irradiation by ultraviolet light or in the presence of peroxides 1 for instance, allyl-amine hydrochloride or a derivative thereof in alcoholic solution is thiolated by an excess of hydrogen sulfide under UV-irradiation, exclusively (yields up to 57%), to give 3-aminoalkanethiols.2 Addition of hydrogen sulfide is of use in the laboratory only when the reaction can be carried out in the liquid phase and is then preferably effected under the influence of a basic catalyst Dahl-bom,3 for instance, obtained 3-mefcapto-butyric acid from crotonic acid hydrogen sulfide in the presence of diethylamine in a closed vessel at 70° and 4-mercapto-4-methyl-2-pentanone is obtained in 80% yield from mesityl oxide and hydrogen sulfide with triethylamine as catalyst.4... 

P. Darriet, T. Tominaga, V. Lavigne, J. N. Boidron, and D. Dubourdieu, Identification of a powerful aromatic component of Vitis vinifera L. var. Sauvignon wines 4-mercapto-4-methyl-2-pentanone, Flav. Fragr. J. 10 385 (1995). 

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