Ion-pair high-performance liquid chromatography separation of β-endorphin-(6–17) from fourteen fragments

Summary In order to support metabolism studies of the proposed antipsychotic compound β-endorphin-(6–17), (Org 5878), the HPLC separation of this parent compound from fourteen peptide fragments was studied. The addition to the mobile phase of hydrophobic ion-pairing agents proved to be necessary to obtain adequate separation. The influence of the chromatographic parameters pH, type and concentration of the pairing agent, buffer concentration and temperature were investigated systematically. As a result the complete separation of Org 5878 and its fourteen fragments is reported.