| Autor: |
John A. W. Kruijtzer, G. Wiese, Oeds A.G.J. van der Houwen, Marnix A. Hoitink, Willy J. M. Underberg, Jos H. Beijnen, Matthijs M. Tibben, J. Mirjam A. Damen, Auke Bult |
| Rok vydání: |
2000 |
| Předmět: |
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| Zdroj: |
Journal of Pharmaceutical Sciences. 89:108-114 |
| ISSN: |
0022-3549 |
| DOI: |
10.1002/(sici)1520-6017(200001)89:1<108::aid-jps11>3.0.co;2-a |
| Popis: |
Three model tripeptides, N-acetyl-Tyr-Pro-azaGly-NH(2) (NYPaG), Tyr-Pro-azaGly-NH(2) (YPaG), and Tyr-Pro-Gly-NH(2)(YPG), were subjected to a systematic degradation study to get information about the degradation of the azaglycinamido residue. The degradation products were characterized with LC-MS. Main degradation products of NYPaG possess partially or totally eliminated azaglycinamido residues, while YPaG and YPG are exhibit cyclo(Tyr-Pro) formation, a diketopiperazine. The influence of the pH on the degradation rate constant k(obs) was investigated for NYPaG and YPaG in the pH range 0.4-11. An U-shaped profile with an inflexion around pH 9 was found for NYPaG while the degradation rate of YPaG was independent of the pH. NYPaG apparently was subject to proton-, solvent-, and hydroxyl-catalyzed degradation reactions whereas YPaG only underwent solvent-catalyzed reactions. Some influence of acetate and phosphate ions on k(obs) was found for YPaG. Arrhenius plots of NYPaG and YPaG were found to be linear. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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