| 摘要 |
A compound, or a pharmaceutically acceptable salt or ester thereof, comprises a ligand for the chemokine receptor CXCR4 and a detectable label, the ligand having a binding affinity for the CXCR4 receptor, measured as IC50 in the presence of 125I-CPCR4, of 25OnM or lower, wherein the ligand comprises a cyclic oligopeptide moiety having the motif B-Arg or B-(Me)Arg within the cyclic moiety, and wherein B is a basic amino acid; a derivative thereof, or phenylalanine, provided that the motif is B-Arg when B is a Nalpha-methyl derivative of a basic amino acid. In preferred embodiments, the cyclic oligopeptide moiety has the sequence: cyclo[D-Tyr/(Me)D-Tyr-B-Arg/(Me)Arg-Z-(Ala)n-X] wherein: B is as defined above; Z is an amino acid containing an aromatic group in its side chain; n is 1 or 0, provided that n is 1 only when the preceding four amino acids in the cyclic moiety sequence are D-Tyr/(Me)D-Tyr-Arg-Arg-Nal, NaI being L-3-(2-naphthyl)alanine; and X is selected from GIy, (Me)GIy, Ala, Dap (diaminopropionic acid), Dap(FP) ((N-fluoropropionyl)-diaminopropionic acid), Dab (diaminobutyiic acid), Dab(FP) ((N-fluoropropionyl)-diaminobutyric acid), Dab(FB) ((N-fluorobenzoyl)-diaminobutyric acid) and Dap(FB) ((N-fluorobenzoyl)-diaminopiOpionic acid). The compounds may be useful for diagnostic imaging and/or therapeutic purposes. |
