692-29-5Relevant articles and documents
Rearrangements and Tautomeric Transformations of Heterocyclic Compounds in Homogeneous Reaction Systems Furfural–Н2О2–Solvent
Badovskaya,Poskonin
, p. 1568 - 1579 (2018/11/10)
General information on the reactions of furfurals with hydrogen peroxide is given. We have discussed the Baeyer–Villiger rearrangement of furan 2-hydroxyhydroperoxides and tautomeric transformations with proton transfer of 2-hydroxyfuran and β-formylacrylic acid formed in a homogeneous reaction system furfural–Н2О2–solvent under the catalysis with the formed acids. The factors affecting these rearrangements and tautomeric transformations as well as their specificity in comparison with benzene type compounds, and the pathway of the reactions of furan aldehydes with Н2О2 in water have been analyzed. Ketoenol tautomerism of cyclic hemiacetal form of β-formylacrylic acid leading to its transformation into succinic anhydride has been described for the first time.
Inhibition of 1,4-butanediol metabolism in human liver in vitro
Lenz, Daniel,Juebner, Martin,Bender, Katja,Wintermeyer, Annette,Beike, Justus,Rothschild, Markus A.,Kaeferstein, Herbert
scheme or table, p. 647 - 654 (2012/06/01)
The conversion of 1,4-butanediol (1,4-BD) to gamma-hydroxybutyric acid (GHB), a drug of abuse, is most probably catalyzed by alcohol dehydrogenase, and potentially by aldehyde dehydrogenase. The purpose of this study was to investigate the degradation of 1,4-BD in cytosolic supernatant of human liver in vitro, and to verify involvement of the suggested enzymes by means of gas chromatography-mass spectrometry. The coingestion of 1,4-BD and ethanol (EtOH) might cause complex pharmacokinetic interactions in humans. Therefore, the effect of EtOH on 1,4-BD metabolism by human liver was examined in vitro. Additionally, the influence of acetaldehyde (AL), which might inhibit the second step of 1,4-BD degradation, was investigated. In case of a 1,4-BD intoxication, the alcohol dehydrogenase inhibitor fomepizole (4-methylpyrazole, FOM) has been discussed as an antidote preventing the formation of the central nervous system depressing GHB. Besides FOM, we tested pyrazole, disulfiram, and cimetidine as possible inhibitors of the formation of GHB from 1,4-BD catalyzed by human liver enzymes in vitro. The conversion of 1,4-BD to GHB was inhibited competitively by EtOH with an apparent K i of 0.56 mM. Therefore, the coingestion of 1,4-BD and EtOH might increase the concentrations and the effects of 1,4-BD itself. By contrast AL accelerated the formation of GHB. All antidotes showed the ability to inhibit the formation of GHB. In comparison FOM showed the highest inhibitory effectiveness. Furthermore, the results confirm strong involvement of ADH in 1,4-BD metabolism by human liver.
Role of chloride in the oxidative decarboxylation of amino acids by chloramine-T
Gowda, B. Thimme,Quine, S. Darlin,Krishna Kumar
, p. 413 - 420 (2007/10/03)
Kinetics of oxidative decarhoxylation of amino acids by chloramine-T in the presence of chloride have been studied in aqueous perchloric acid over a wide range. The rate-[H+] plots show nearly bell-shaped profiles in the presence of added chloride. The rate-dependence in [CAT] changes from second order to first order as [H+] and [Cl-] are varied. The reactions generally show fractional order kinetics in [AA] and inverse dependence in [H+] except in the acid range 0.05-0.20 mol dm-3. Mechanisms consistent with the observed results are discussed. The rate-limiting steps have been identified and constants of these steps calculated. Activation parameters corresponding to these steps have also been computed. Validity of Taft equation has been tested. The study establishes the significant role of chloride in chloramine-T oxidations in acid medium. The chloride effect is more pronounced at high acid concentrations.
