GB880245A - New polypeptides - Google Patents

Abstract

The invention comprises L-arginyl- or L-ornithyl- or L-lysyl-L-a -lower alkyl-a -amino-acetyl-L-tyrosyl-L-a -lower alkyl -a -aminoacety L-histidyl-L-prolyl-L-phenyl-alanines, in which the lower alkyl groups each contain 1-5 carbon atoms, and physiologically tolerable acid addition salts thereof. The L-a -lower alkyl-a -aminoacetyl residue is L-valyl, L-norvalyl, L-leucyl, L-isoleucyl, L-nor-isoleucyl, or L-alanyl. The peptides are obtained by methods known per se for making peptides, the amino acids being linked together in the aforesaid series singly or after being linked in small peptide units. Thus, N-carbobenzyloxy-L-arginine is condensed with L-valyl-L-tyrosyl-L - valyl - L - histidyl - L - prolyl - L - phenylalanine methyl ester in the presence of dicyclohexylcarbodiimide to give the N-carbobenzyloxy heptapeptide methyl ester which is hydrolysed by acid to the free heptapeptide. Similarly N-carbobenzyloxy-nitro-L-arginine is reacted with the same hexapeptide ester to give the corresponding N-substituted heptopeptide ester which is hydrogenated to give the free peptide ester then hydrolysed to the free peptide. Specification 876,571 is referred to.ALSO:Pharmaceutical preparations having hypertensive action comprise lambda-arginyl or lambda-ornithyl-or lambdalysyl - lambda - a - lower alkyl - a - aminoacetyl - lambda - tyrosyl - lambda - a - lower alkyl - a -aminoacetyl - lambda - histidyl - lambda - prolyl - lambda - phenylalanines and physiologically acceptable acid addition salts (wherein lower alkyl groups contain 1-5 carbon atoms) in admixture or conjunction with a pharmaceutical carrier suitable for enteral or parenteral administration. Lower alkyl-a -aminoacetyl groups include lambda-valyl, lambda-nouvalyl, lambda-leucyl lambda-nor-isoleucyl, lambda-iso-leucyl or lambda-alanyl. The preparations may be in the form of tablets, dragees, powders, salves, creams, suppositories, solutions, suspensions or emulsions. They may contain other therapeutically active substances. Specification 876,571 is referred to.