Patent ID: 8501687

Claim:
A cyclic somatostatin(SRIF) peptide antagonist which selectively binds the SRIF receptor SSTR2 without triggering internalization into a cell, which peptide comprises: the amino acid sequence (cyclo3-14)Xaa 1 -Xaa 2 -D-Xaa 3 -Xaa 4 -Xaa 5 -Xaa 6 -Xaa 7 -Xaa 8 -Xaa 9 -Xaa 10 -Xaa 11 -Xaa 12 -Xaa 13 -Xaa 14 -Xaa 15 wherein: Xaa 1 is des-Xaa; Xaa 2 is pNO 2 -Phe or Cpa; D-Xaa 3 is D-Cys, D-HCys or another D-isomer α-amino acid having an SH-side chain; Xaa 4 , Xaa 5 and Xaa 6 are des-Xaa; Xaa 7 is Aph(Hor), Aph(Cbm), Tyr or ITyr; Xaa 8 is D-Trp or D-Aph(Cbm); Xaa 9 is Lys; Xaa 10 is Thr, Ser or Val; Xaa 11 , Xaa 12 and Xaa 13 are des-Xaa; Xaa 14 is Cys, hCys or another L-isomer α-amino acid having an SH side chain; and Xaa 15 is 2Nal, D-2Nal, Tyr, or D-Tyr.