7696-05-1Relevant articles and documents
Bacterial flavoprotein monooxygenase YxeK salvages toxic S-(2-succino)-adducts via oxygenolytic C–S bond cleavage
Ellis, Holly R.,Kammerer, Bernd,Lagies, Simon,Matthews, Arne,Sch?nfelder, Julia,Schleicher, Erik,Stull, Frederick,Teufel, Robin
, (2021/10/06)
Thiol-containing nucleophiles such as cysteine react spontaneously with the citric acid cycle intermediate fumarate to form S-(2-succino)-adducts. In Bacillus subtilis, a salvaging pathway encoded by the yxe operon has recently been identified for the detoxification and exploitation of these compounds as sulfur sources. This route involves acetylation of S-(2-succino)cysteine to N-acetyl-2-succinocysteine, which is presumably converted to oxaloacetate and N-acetylcysteine, before a final deacetylation step affords cysteine. The critical oxidative cleavage of the C–S bond of N-acetyl-S-(2-succino)cysteine was proposed to depend on the predicted flavoprotein monooxygenase YxeK. Here, we characterize YxeK and verify its role in S-(2-succino)-adduct detoxification and sulfur metabolism. Detailed biochemical and mechanistic investigation of YxeK including 18O-isotope-labeling experiments, homology modeling, substrate specificity tests, site-directed mutagenesis, and (pre-)steady-state kinetics provides insight into the enzyme’s mechanism of action, which may involve a noncanonical flavin-N5-peroxide species for C–S bond oxygenolysis.
Preparation method of N-acetyl-L-cysteine
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Paragraph 0013-0017, (2019/05/15)
The invention belongs to the field of organic synthesis and particularly relates to a preparation method of N-acetyl-L-cysteine. In the method, with cysteine being a raw material and acetic anhydridebeing an acylating agent, the N-acetyl-L-cysteine is prepared through a one-step direct acylation reaction. In the method, the optimum pH value range is disclosed and a recrystallization reagent is determined; meanwhile, by means of a sectional temperature control method, the yield and mass percentage of the product are greatly increased, wherein the finish yield of the product is 80-85% and the mass percentage can reach more than 99%. The method can greatly reduce production cost and reaction steps, and has excellent industrial prospect.
COMPOSITIONS AND METHODS FOR THE TREATMENT OF COUGH
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Paragraph 0115, (2015/05/26)
The invention relates to the compounds of formula I or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compounds of formula I, and methods for treating or preventing cough may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, syrup, or injection. Such compositions may be used to treatment of acute respiratory tract infections, asthma, gout, fibromyalgia, facilitating conception, promotes secondary mucosal secretions in the respiratory system, muscle relaxant, allergy, asthma, chronic obstructive pulmonary disorders, spasms, respiratory and neurological diseases.