PEPTIDES, PROCESS FOR THEIR PREPARATION AND MEDICAMENTS OR DIAGNOSTIC AGENTS CONTAINING THEM

摘要

New octapeptides of the general formula (I), X-Arg-Val-Tyr-Ile-His-Pro-Y-OA (I) wherein X stands for the acyl group of an N-methylamino acid or the acyl group of an aliphatic alpha -hydroxy- or alpha -aminooxycarboxylic acid, Y is the residue of an aliphatic amino acid, and A is a C1-5 alkyl group, are prepared so that the protecting groups of a protected octapeptide derivative of the general formula (II), B-X-Arg(C)-Val-Tyr(D)-Ile-His(E)-Pro-Y-OA (II) wherein B is a group removable by acidolysis or catalytic hydrogenation, C is a group for the temporary protection of the guanidino group on the Arg moiety, D is a group for the temporary protection of the aromatic hydroxy group on the Tyr moiety, E is a group for the temporary protection of the imidazole group on the His moiety, and A, X and Y are as defined above, are removed either stepwise or in a single step. If desired, a compound of the general formula (I) is converted into its acid addition salt or pharmaceutically acceptable complex. The new compounds according to the invention possess angiotensin-II antagonizing effects, and can be used in the therapy to diagnose or treat hypertensive states.