Mass spectrometric and kinetics characterization of modified species of Growth Hormone Releasing Hexapeptide generated under thermal stress in different pH and buffers.
J Pharm Biomed Anal
; 194: 113776, 2021 Feb 05.
Article
en En
| MEDLINE
| ID: mdl-33272786
ABSTRACT
Growth Hormone Releasing Peptide-6 (GHRP-6) is a promising molecule (H-His1-d-Trp- Ala-Trp-d-Phe-Lys6-NH2) for the treatment of several diseases. Studies on the degradation pathways of this molecule under stressed conditions are needed to develop appropriate formulations. Degradation products (DPs) of GHRP-6, generated by heating in the dark at 60 °C with pH ranging from 3.0 to 8.0 and in presence of common buffers, were isolated by RP-HPLC and characterized by ESI-MS/MS. C-terminal deamidation of GHRP-6 was generated preferentially at pH 3.0 and 8.0. Hydrolysis and head-to-tail cyclization were favored at pH ranging from 6.0 to 7.0 in phosphate containing buffers. A DP with +12 Da molecular mass was presumably originated by the reaction with formaldehyde derived from some of the additives and/or elastomeric closures. Certain DPs derived from the acylation reaction of the tri- and di-carboxylic buffering species were favored at pH 3.0-6.0 and indicate that buffer components, including those "Generally Recognized as Safe", may potentially introduce chemical modifications and product heterogeneity. Nano LC-MS/MS analysis revealed GHRP-6 was also detected as a low-abundance species with Trp oxidized to 5-hydroxy, kynurenine, and N-formylkynurenine. The kinetics for the formation of the major degradation products was also studied by RP-HPLC.
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1
Bases de datos:
MEDLINE
Asunto principal:
Hormona Liberadora de Hormona del Crecimiento
/
Espectrometría de Masas en Tándem
Idioma:
En
Revista:
J Pharm Biomed Anal
Año:
2021
Tipo del documento:
Article
País de afiliación:
Cuba