Patent AU-6627681-A (AU)
Title: Octapeptide of angiotensin-02 antagonizing effects
Inventor: NYEKI O
IPC: A61K38/55
Filed: 1981-01-16
Abstract: 1. Claims for the contracting States : BE, CH, LI, DE, FR, GB, IT, NL, SE, Peptides having the general formula X-Arg-Val-Tyr-Ile-His-Pro-Y-O-A wherein X represents an acyl radical of a N-methyl-aminoacid or of an aliphatic carboxylic acid having in the alpha-position an aminooxy group or a hydroxyl group, each in the L-configuration in case of an asymmetrical carbon atom, Arg represents a radical of L-arginine, Val represents a radical of L-valine, Tyr represents a radical of L-tyrosine, Ile represents a radical of L-isoleucine, His represents a radical of L-histidine, Pro represents a radical of L-proline, Y represents a radical of an aliphatic alpha-hydroxycarboxylic acid having 1 lacking hydrogen atom of its hydroxyl group with respect of this acid beyond the absence of the hydroxyl group of the carboxylic group and A represents hydrogen or an alkyl radical having from 1 to 5 carbon atom(s), as well as their acid addition salts and pharmaceutically useful complexes. 1. Claims for the contracting state AT A process for the preparation of peptides having the general formula X-Arg-Val-Tyr-Ile-His-Pro-Y-O-A wherein X represents an acyl radical of a N-methyl-aminoacid or of an aliphatic carboxylic acid having in the alpha-position an aminooxy group or a hydroxyl group, each in the L-configuration in case of an asymmetrical carbon atom, Arg represents a radical of L-arginine, Val represents a radical of L-valine, Tyr represents a radical of L-tyrosine, Ile represents a radical of L-isoleucine, His represents a radical of L-histidine, Pro represents a radical of L-proline, Y represents a radical of an aliphatic alpha-hydroxycarboxylic acid having 1 lacking hydrogen atom of its hydroxyl group with respect of this acid beyond the absence of the hydroxyl group of the carboxylic group and A represents hydrogen or an alkyl radical having from 1 to 5 carbon atom(s), as well as of their acid addition salts and pharmaceutically useful complexes, characterized in that one condenses in a manner known per se in the peptide chemistry a propper aliphatic alpha-hydroxyl carboxylic acid or a propper alkyl ester of it having from 1 to 5 carbon atoms in the alkyl part or another ester of it only with a protective function of the ester group with the amino acid to be incorporated successively and having on its terminal nitrogen atom a splittable-off protective group and, as far as necessary, on another nitrogen atom being optionally present another splittable-off protective group and/or with the peptide fragment or an ester derivative of it, respectively, successively to be incorporated and having on its terminal nitrogen atom a splittable-off protective group and, as far as necessary, on one or several other nitrogen and/or oxygen atom(s) one or several protective group(s) and, if desired, one carries out with the obtained peptide intermediate protected on the terminal nitrogen atom and with the further peptide intermediate(s) obtained by possible further condensations of this type and protected on the terminal nitrogen atom after having removed the protective group of the terminal nitrogen atom one further condensation or further condensations, respectively, with the amino acid or with the respective amino acid, respectively, successively to be incorporated and having on its terminal nitrogen atom a splittable-off protective group and, as far as necessary, on another nitrogen atom or oxygen atom optionally present another splittable-off protective group and/or with the peptide fragment or an ester derivative of it, respectively, successively to be incorporated and having on its terminal nitrogen atom a splittable-off protective group and, as far as necessary, on one or several other nitrogen and/or oxygen atom(s) optionally present one or several protective group(s) accomplishing as much condensations as are necessary for incorporating all desired amino acid units as well as thereafter in a manner known per se selectively step by step or in one step one removes from the obtained protected peptide derivative the protective group of the terminal nitrogen atom and the possible protective group(s) of other nitrogen atoms or oxygen atoms, respectively, as well as, if desired, the amino group of the aminooxy group optionally present, whereafter, if desired, in a manner known per se one converts the obtained peptide of the general formula I into an acid addition salt or into a complex of it or, if desired, the obtained acid addition salt of the peptide of the general formula I into another acid addition salt or in the peptide of the general formula I, respectively.