摘要 |
The present invention relates to a method of synthesizing a peptide product comprising at least one cyclic imide group. Further, the invention relates to a peptide product comprising at least one cyclic imide group, which is substantially free from degradation products. The peptide product may be used as a reference material for the quality control of pharmaceutical peptides, particularly for the quality control of a GLP-1 agonist like exendin peptides. |