| abstract |
The present invention relates to novel somatostatin analogues of the general formula (I) wherein Z may be absent or present and when present is selected from the group consisting of DOTA- and DTPA- based chelators, NOTA-based chelators, carbonyl compounds, hydrazino nicotinamide (hynic) , N4-chelators, desferrioxamin, NxSy-chelators, all optionally complexed or labeled with a radioisotope, Tyrosine (Tyr) for halogenation, a fluorescent dye or biotin; L may or may not be present and is a linker molecule; X1 is a syrnmetric or asyrnmetric diamino acid, containing 3 or 4 consecutive C atoms with a linker to the chelating agent, for example D/L-diamino butyric acid (D/L-Dab) for a more basic character or D/L-Glu for coupling to primary and secondary amino groups; X2 is a positively charged natural or unnatural amino acid or arginine mimic or citrulline, or a neutral amino acid like Asn; X3 is phenylalanine (Phe) , Ala-[3-(2-thienyl)] or .alpha.-,.beta.-naphthylalanine; X4 is an aromatic amino acid, optionally halogenated, in particular with C1, Br, I or l8F; X5 is threonine (Thr) or serine (Ser); and X6 is phenylalanine (Phe) , Ala-[3-(2-thienyl)] or .alpha.-,.beta.-naphthylalanine. |