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Acid-base properties of pristinamycin IA and related compounds
1Laboratoire de Chimie Analytique et Electrochimie, Centre National de la Recherche Scientifique, 1310, Faculte de Pharmacie, Paris, France.
Journal of Pharmaceutical Sciences
|June 1, 1992
Abstract:
The pKa values of acid-base equilibria involved in the protonation of pristinamycin IA and its model compound, N-isobutyl-3-hydroxypicolinamide, were determined by UV-visible absorption spectrometry and potentiometric titration. The equilibrium between dipolar ionic and uncharged neutral forms was investigated spectrometrically in methanol-water solutions. With pristinamycin IA, the dipolar ionic form predominated in aqueous solutions buffered to the isoelectric pH. The effects of structure on the ionization constants are briefly discussed.