FIELD: organic chemistry, peptides, pharmacy.
SUBSTANCE: invention relates to biologically active compounds as antagonists of somatostatin. Invention represents compound of the formula (I): A1-cyclo-{D-Cys-A2-D-Trp-A3-A4-Cys}-A-Y1 wherein A1 represents aromatic α-amino acid taken among the group: Cpa, Tfm, 1-Nal, 2-Nal and 3-Pal and substituted optionally with one or some substitutes taken among halogen atom and (C1-6)-alkyl; A2 represents aromatic amino acid taken among the group: 3-Pal and Tyr and substituted optionally with one or some substituted taken among halogen atom, (C1-6)-alkyl, OH-group; A3 represents Lys, Dab, Dap, Orn; A4 represents Thr, β-hydroxyvaline, Ser, Hser; A5 represents D- or L-aromatic α-amino acid taken among the group: Dip, 2-Nal, Trp; Y1 represents -NH2 or -MHMe wherein amine nitrogen in each amide peptide bond and amino-group A1 are substituted optionally with methyl group under condition that at least one abovementioned methyl group presents; or its pharmaceutically acceptable salt.
EFFECT: valuable biological properties of compounds.
11 cl, 1 dwg, 3 tbl, 16 ex
