Investigation of crudes of synthesis of carbetocin by liquid chromatography coupled to electrospray ionization mass spectrometry

Synthetic peptides are becoming increasingly important as drugs in the pharmaceutical industry. Stepwise solid-phase peptide synthesis, commonly results in unwanted side products associated with incomplete peptide chains. Here, LC-electrospray MS has been used to examine a crude of synthesis of carbetocin, a peptide with recognized therapeutical application for stimulation of uterine contractions to facilitate parturition. The molecular masses of various side products obtained within the crude of synthesis have been determined and these side products have been identified on the basis of their molecular masses. The knowledge of the impurities present in the crude peptide permits the optimization of the synthetic procedure. (C) 1999 Published by Elsevier Science B.V. All rights reserved.