Cyclic polypeptides having mu-receptor specificity

摘要: Novel compounds which are capable of binding with enhanced specificity to the mu opioid receptor disclosed. The analogs somatostain and have formula: ##STR1## wherein X is CONH 2 or CH OH; Y Z independently sulfur ; R 1 , may be same different, hydrogen, methyl, ethyl, cyclopentamethylene, a lower alkyl group having five less carbon atoms; 3 4 atoms, provided, however, that not all hydrogen; AA Phe, D-Phe, phenyl-Gly, D-phenyl-Gly, Tyr, D-Tyr, L-1-Naphthylalanine, D-1-Naphthylalanine, D-Phe(4-Me); Tyr(OMe), Phe(4-Me), Tyr(OEt), Phe(4-Et); Lys, Arg, Orn homo-Arg. novel antagonist activity used induce pharmacological therapeutic effects in humans other animals.