Synthesis and properties of equine β-melanotropin analogs with substitution in residue position 1

Five analogs of equine β-melanotropin have been synthesized by the solid phase method. The NH₂-terminal aspartic acid was substituted with amino acids (Gly, Trp, Ile, Lys and Nα-acetyl-Asp) differing widely in physicochemical properties. On the basis of their lipolytic potencies it was concluded that this position plays a negligible role in this activity.