Ion-pair RP-HPLC separation of thymopoietin fragments and related peptides

Reversed phase HPLC methods have been developed for the separation of related peptides from two synthetic thymopoietin fragments: thymotrinan (Arg-Lys-Asp) and thymocartin (Arg-Lys-Asp-Val), as experimental immunostimulant drugs. The optimization of the method using different octadecylsilica columns, acidic buffer and hexanesulphonate as the ion-pairing reagent has led to a method which is suitable to solve delicate problems such as the separation of diastereomeric and isopeptide derivatives. Preliminary experiments have shown that similar results can be obtained using perchlorate as the ion-pairing reagent.