[A granulopoiesis inhibitor. Synthesis and biological activity]

Three schemes of synthesis for pentapeptide Glp-Glu-Asp-Cys-Lys-OH were compared was carried out. Acetamidomethyl protection was used for the mercapto group of cysteine. For the same purpose, cystine was used as the starting compound for synthesis. The optimal method was shown to be the solid phase method with S-acetamidomethyl cysteine protection that can be removed by mercuric acetate before the cleavage of a peptide from a polymer. The stabilized peptide inhibits proliferation of bone marrow cells of patients with chronic myeloleukemia 5- to 20-fold and has a less pronounced effect (up to 2-fold inhibition) on peripheral blood cells. Thus, its application for the therapy of hemoblastoses is promising.