Glutathione ethyl ester

Wen B, Fitch WL (2009) Screening and characterization of reactive metabolites using glutathione ethyl ester in combination with Q-trap mass spectrometry. J Mass Spectrom 44 90-100... 

Af-Acetoxy-Af-butoxybenzamide (145, R = Bu, = Me) reacted with glutathione in DMS0-t/6/D20 and with (L)-cysteine methyl and ethyl esters in methanol-tij. NMR studies indicated a bimolecular process, with thiol consumed at twice the rate of Af-acyloxy-A-alkoxyamide. Like the Al-aminohydroxamic esters described in the previous section, the intermediate A-thioalkylhydroxamic ester (146) is also unstable, being susceptible to a non-rate-determining, secondary nucleophilic reaction with the reactive thiol . ... 

Rates of reaction were moderately fast. Glutathione reacted rapidly in DMS0-rf6/D20 ( 2 ° ca 2 X 10 lmol s ) and a series of A-benzoyloxy-A-benzyloxybenzamides (139) and (L)-cysteine ethyl ester in methanol-(f4 reacted with low a values (8-16 kcal mol ) and negative AS (—19 to —43 calK mol ), similar to their reaction with anilines. Bimolecular rate constants at 298 K (Table 8) correlated positively with Hammett a constants with slightly lower sensitivity p =. as opposed to p =. l for A-methylaniline). ... 

At about the same time, a synthesis of leukotriene-A, also termed SRS-A ( slow reacting substance of anaphylaxis ), which made use of the Wittig olefmation was described77). The ylide of 100 is reacted with ethyl 5-formyl-2,4-pentadienoate 101 to give the ( , , Z, Z)- tetraenoic ester 102. Reduction and mesylation of 102, subsequent conversion into the sulfonium salt, and treatment of the latter with a base yields a sulfonium ylide which is reacted with methyl 4-formylbutanoate 69 to the epoxy-tetraenoic ester 103. After separation of the cis-epoxide by HPLC, 103 was treated with the S-trimethylsilyl derivative of glutathione dimethyl ester N-trifluoroacet-amide. The diastereomeric products thus obtained were separated by means of HPLC and hydrolyzed to 104 77) (Scheme 18). 

For example, an isozyme of glutathione-S-transferase will also catalyze the fatty acid ethyl-ester synthase reaction, leading to the formation of ethyloleate from oleic acid and ethanol (Bora et al. 1989). Also, phospholipase D catalyzes the transphosphatidylation of phosphatidylcholine with ethanol to form phosphatidylethanol (Kobayashi and Kanfer 1987). The active site requirements and kinetics of the hydrolases or transferases that catalyze these ethylation reactions are not well understood. The elucidation of mechanisms and active site structures for enzyme-catalyzed... 

Board P, Smith S, Green J, Coggan M, Suzuki T. Evidence against relationship between fatty acid ethyl ester synthase and the pi class glutathione S-transferase in humans. J Biol Chem 1993 268 15,655-15,658. 

Bora PS, Spilburg CA, Lange LG. Identification of a satellite fatty acid ethyl ester synthase from human myocardium as a glutathione S-transferase. J Clin Invest 1989 84 1942-1946. 

Sharma R, Gupta S, Singhal SS, Ahmad H, Ilaque A, Awasthi YC. Independent segregation of glutathione S -hansferase and fatty acid ethyl ester synthase from pancreas and other human tissues. B iochem J 1991 275 507-513. 

Glutathione mono-ethyl ester has also been used often in research to rapidly restore intracellular GSH levels. The drawback to using GSH ester as a therapy for diseases associated with glutathione depletion is that it provides intracel-lularly equimolecular amounts of ethanol together with GSH. 

Joshi, G., S. Hardas, R. Sultana et al. Glutathione elevation by ganuna-glutamyl cysteine ethyl ester as a potential therapeutic strategy for preventing oxidative stress in brain mediated by in vivo administration of adriamycin Implication for chemobrain. 

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