Abstract: A process for the solid phase synthesis of peptides containing a C-terminal aza-amino acid, for example the decapeptide goserelin, which comprises:(i) reacting an active ester or imidazolide of an N-protected aza-amino acid either with an appropriate reactive solid support in the case of the synthesis of a peptide containing a C-terminal aza-amino acid, or with a peptide which is attached to a solid support in the case of the synthesis of a peptide containing a non-C-terminal aza-amino acid;(ii) carrying out further conventional solid phase peptide synthesis steps to add sequentially further amino acids, to form a peptide with the required amino acid sequence bound to the solid support;(iii) cleaving the peptide from the solid support, and optionally(iv) reacting the product so formed with hydrazine to remove any acyl groups which have been formed on serine, arginine, tyrosine, threonine or hydroxyproline during the synthesis.

Abstract: Compounds of the formula: ##STR1## wherein R.sup.1 stands for an alk-2-enyl radical of not more than 5 carbon atoms or a furylmethyl radical, R.sup.2 stands for an alk-2-enyl or alkyl radical of not more than 5 carbon atoms or a furylmethyl radical, >N--A, B, D, E and F stand for defined amino acid or aza-amino-acid residues, and in particular one or both of B and D stand(s) for an amino acid residue of the formula --NH.C(1-3C alkyl)(1-3C alkyl).CO-- or a similar residue, and X stands for --OR.sup.7 or --NR.sup.7 R.sup.8, wherein R.sup.7 and R.sup.8, which may be the same or different, stand for hydrogen or a (1-4C)alkyl radical, and wherein the linkages are all conventional peptide linkages or in the case of D-E the peptide linkage is replaced by the group --CH.sub.2 S--, and pharmaceutically-acceptable salts thereof. Processes for the manufacture of the compounds. Pharmaceutical compositions comprising one of the compounds and a pharmaceutically-acceptable diluent or carrier.

Abstract: The disclosure relates to novel polypeptides which are analogues of luliberin and which possess luliberin antagonist activity, to processes for their manufacture and to compositions containing them. Typical of the polypeptides disclosed is ##STR1## in which A is D-Phe, D-Trp or a direct bond.