A kinetic study of the acid hydrolysis of aqueous diazepam, bromazepam, and flunitrazepam was carried out at 25 degrees C using a spectrophotometric method. For diazepam and flunitrazepam, the experimental pseudo first-order rate constant decreased as the acid concentration was increased. The contrary behavior was found in the case of bromazepam. A kinetic scheme that includes the hydrolysis reaction of both protonated and nonprotonated species of the drug can account for these results. Also, the kinetics of the acid hydrolysis of the same drugs in the presence of micellar aggregates [nonionic polyoxyethylene-23-dodecanol (Brij 35); cationic cetyl trymethyl ammonium bromide (CTAB); and anionic sodium decyl (SdeS), dodecyl (SDS), and tetradecyl (STS) sulfate] was studied at 25 degrees C. Negligible effects were observed in the cases of nonionic and cationic micelles. Anionic micelles produced an inhibitory effect in the reaction velocity. This effect increased as the hydrophobic nature of the surfactant increased. All these facts are interpreted quantitatively by means of a pseudophase model.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jps.2600800513 | DOI Listing |
Food Chem X
January 2025
College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China.
The quality and flavor of Liuyang Douchi are usually closely related to the metabolites compostion. This work described the metabolic profiles of Liuyang douchi during fermentation. Obvious hydrolysis of carbohydrates, proteins and slight lipids degradation were observed.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia. Electronic address:
The acidity of historic paper, a property crucial for its preservation, is thought to mainly depend on the type of sizing. However, this research shows that during its degradation, paper acidity increases mainly due to the formation of non-volatile carboxylic acids, which accelerate acid-catalysed hydrolysis. Whether and how this accumulation depends on paper composition has not been studied systematically so far.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, China; Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, School of Pharmacy, Air Force Medical University, Xi'an 710032, China. Electronic address:
Alcoholic fatty liver disease (AFLD) is characterized by the accumulation of hepatic lipid and has no effective treatment yet. Fructus Corni is a traditional Chinese medicinal herb, and its extractions have demonstrated hepatoprotective properties. We hypothesize that the polysaccharides in Fructus Corni might have therapeutic effects on AFLD.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Department of Energy, Environmental & Chemical Engineering Washington University in St. Louis, St. Louis, Missouri 63130, United States.
The hydrolysis rates of many organic chemicals are accelerated under alkaline conditions by the presence of hydroxide (HO), which is typically assumed to be the predominant species contributing to base-catalyzed hydrolysis in both natural waters and laboratory buffers used in standard protocols. In this study, we demonstrated that weak bases (e.g.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Ankang Research and Development Center for Se-Enriched Products, Ankang 725000, China.
Selenopeptides can be ideal dietary selenium (Se) supplements for humans. Currently, rice is not used much as a source of selenopeptides. Here, we executed the selenopeptidomics analysis of selenium-enriched rice protein hydrolysates using the full MS-dd-MS2 acquisition method and identified selenopeptides, including L{Se-Met}AK and other selenopeptides.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!