Studies on Peptides. XXII. Synthesis of the partially Protected Pentadecapeptide related to Monkey and Human β-Melanocyte-stimulating Hormones

抄録

Synthesis of the partially protected pentadecapeptide related to monkey and human β-melanocyte-stimulating hormone, H-Pro-Tyr-Arg-Met-Glu-His-Phe-Arg-Trp-Gly-Ser-Pro-Pro-Lys (N^ε-formyl)-Asp-OH (III), was described. Condensation of Z-Glu (γ-OBzl)-OH with H-His-Phe-Arg-Trp-Gly-Ser-Pro-Pro-Lys (N^ε-formyl)-Asp-OH (IV) by the p-nitrophenyl ester method and subsequent hydrogenation gave H-Glu-IV, which was condensed with Boc-Met-OH by the same procedure. Treatment of the product with trifluoroacetic acid gave H-Met-Glu-IV. Boc-Arg (N^G-nitro)-OH was condensed with this dodecapeptide by the mixed anhydride procedure and the product was treated with hydrogen fluoride to give H-Arg-Met-Glu-IV, to which Boc-Pro-Tyr-OH was added by the azide procedure to afford the protected III. Treatment of which with trifluoroacetic acid gave III. The MSH activity of the synthetic peptides was as follows ; H-Glu-IV, 6.0×10⁶ : H-Met-Glu-IV, 1.9×10⁶, 2.3×10⁷ : H-Arg-Met-Glu-IV, 1.8×10⁸ and III, 2.2×10¹²units/g.