ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    ISSN: 1573-904X
    Schlagwort(e): nitro radical anion ; nisoldipine ; cyclic voltammetry ; EPR spectroscopy ; thiol ; scavenging
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Purpose. To determine the formation of the one-electron reduction product from nisoldipine and its reactivity with relevant thiols in mixed medium. Methods. Cyclic voltammetry (CV) and electron paramagnetic resonance (EPR) techniques were used to determine the one-electron reduction product corresponding to the nitro radical anion. CV was employed to assess both the rate constants corresponding to the decay of the radicals and its interaction with relevant thiols. Results. The nisoldipine radical anion follows second order kinetics, with an association rate constant of 283 ± 161mol−1 sec−1.Nitro radical anion from nisoldipine significantly reacted with thiol compounds. This reactivity was significantly higher than the natural decay of the radical in mixed medium. EPR spectra recordedin situ using DMF/ 0.1 N NaOH (pH 13) confirmed the formation of the nitro radical anion, giving a well-resolved spectra in 35 lines using 0.1 G modulation. Conclusions. Electrochemical and EPR data indicated that all the tested thiols scavenged the nitro radical anion from nisoldipine. The following tentative order of reactivity towards the thiols can be proposed: cysteamine ∼ glutathione 〉N-acetylcysteine 〉captopril 〉penicillamine.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1040-0397
    Schlagwort(e): Nimesulide ; Voltammetry ; Drug analysis ; Differential pulse polarography ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Nimesulide, N-(4-nitro-2-phenoxyphenyl)methanesulfonamide is an antiinflamatory analgesic agent that is both reducible at the mercury electrode and oxidizable at the glassy carbon electrode. Nimesulide in hydroalcoholic solution, presents cathodic response in a wide range of pH (2-12), both, by differential pulse and tast polarography techniques. The obtained results show only one main well-defined peak or wave in all the pH range studied. This peak (or wave) corresponds to the nitro group reduction in position 4. The voltammetric oxidation shows one well-resolved signal in all the pH range studied. This anodic signal could be attributed to the methylsulfonamide group oxidation. For analytical purposes, a very well resolved diffusion controlled differential pulse polarographic peak obtained at pH 7 was selected. This peak was used to develop a new method for the determination of nimesulide in pharmaceutical dosage forms. The recovery study (104.8% with a RSD of 1.3%) shows that the method is sufficiently accurate and precise to be applied in the individual tablet assay of commercial samples.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...