Abstract: Novel peptide compounds of the formulaGlu-His-X.sup.3 -X.sup.4 -X.sup.5 -X.sup.6 -X.sup.7 -X.sup.8 -Pro-Ware provided together with their acid addition salts and their complexes with pharmaceutically acceptable metals. The compounds are LH-RH analogues and together with their salts and complexes exhibit LH-RH agonist activity. In the formulaX.sup.3 and X.sup.5 are the same or different and each is phenylalanyl optionally substituted in the benzene ring;X.sup.4 and X.sup.6 are the same or different and each is selected from glycyl, alanyl (D- or L-) and asparaginyl;X.sup.7 is a radical of a neutral hydrophobic non-sulphur containing non-heterocyclic amino acid;X.sup.8 is a radical of a basic amino acid or is glycyl or phenylalanyl optionally substituted in the benzene ring; andW is selected from glycine amide and a group --NR.sup.1 R.sup.2.All references are to the L-amino acids and their radicals except in the case of glycine and unless otherwise stated.

Abstract: Novel peptide compounds of the formulaX.sup.1 --X.sup.2 --X.sup.3 --X.sup.4 --X.sup.5 --X.sup.6 --X.sup.7 --X.sup.8 --Pro--Ware provided together with their acid addition salts and their complexes with pharmaceutically acceptable metals. The compounds are LH-RH analogues and together with their salts and complexes exhibit LH-RH antagonist activity.In the formulaX.sup.1 is selected from pyroglutamyl, a group V.sup.1 -Pro- where V.sup.1 is acyl, alkyloxycarbonyl or aralkyloxycarbonyl, and a group V.sup.2 --CO-- where V.sup.2 is cycloalkyl;X.sup.2 is selected from histidyl and a direct bond;X.sup.3 is selected from phenylalanyl optionally substituted in the benzene ring and tryptophyl;X.sup.4 is selected from glycyl, seryl, alanyl (D- or L), D-leucyl and D-valyl;X.sup.5 is phenylalanyl optionally substituted in the benzene ring;X.sup.6 is selected from glycyl, alanyl (D- or L-), D-leucyl and D-valyl;X.sup.7 is selected from phenylalanyl optionally substituted in the benzene ring and leucyl;X.sup.

Abstract: Novel peptide compounds of the formulaGlu-His-X.sup.3 -X.sup.4 -X.sup.5 -X.sup.6 -X.sup.7 -X.sup.8 -Pro-Ware provided together with their acid addition salts and their complexes with pharmaceutically acceptable metals. The compounds are LH-RH analogues and together with their salts and complexes exhibit LH-RH agonist activity. In the formulaX.sup.3 and X.sup.5 are the same or different and each is phenylalanyl optionally substituted in the benzene ring;X.sup.4 and X.sup.6 are the same or different and each is selected from glycyl, alanyl (D- or L-) and asparaginyl;X.sup.7 is a radical of a neutral hydrophobic nonsulphur containing non-heterocyclic amino acid;X.sup.8 is a radical of a basic amino acid or is glycyl or phenylalanyl optionally substituted in the benzene ring; andW is selected from glycine amide and a group --NR.sup.1 R.sup.2.All references are to the L-amino acids and their radicals except in the case of glycine and unless otherwise stated.