Patent ID: 7960342

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 i is des-Xaa; Xaa 2 is Trp(A), Phe(B), Nal or Tyr, where A is H, Cl, F, Br, Me, NO 2 , OMe or N-formyl and B is H, halogen, CH 3 , NO 2 , or OCH 3 ; D-Xaa 3 is D-Cys, D-Pen, 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(Q 1 ), Tyr(X), Ala(thienyl) or Trp(A) where Q 1 is Cbm, OH-Cbm, CH 3 -Cbm, OCH 3 -Cbm, OEt-Cbm, Cbm-Et(OEt) 2 or Hor, A is H, Cl, F, Br, Me, NO 2 , OMe or N-formyl, and where X is H or halogen; Xaa 8 is Trp(5F), Trp(5Cl), Trp(5Br), Trp(5Me), Trp(5OMe), Trp(6F), Trp(6Cl), Trp(6Br), D-Trp(5F), D-Trp(5Cl), D-Trp(5Br), D-Trp(5Me), D-Trp(5OMe), D-Trp(6F), D-Trp(6Cl), D-Trp(6Br), Tyr, D-Tyr, Phe(B), D-Phe(B), L or D-BzlHis, L or D-(DNP)His, L or D-Aph(Cbm); Xaa 9 is Lys, N α MeLys, hLys, N α MehLys, Orn or N α MeOrn; Xaa 10 is Thr, Ser or Val; Xaa 11 , Xaa 12 and Xaa 13 are des-Xaa; Xaa 14 is Cys, Pen, hCys or another L- isomer α-amino acid having an SH side chain; and Xaa 15 is 2Nal, D-2Nal, Aph(Q 2 ), D-Aph(Q 2 ), (R 1 )Cha, (R 1 )D-Cha, (R 1 )Leu, (R 1 )D-Leu, Tyr, D-Tyr, Trp, D-Trp or des-Xaa; where R 1 is H or C α Me, and Q 2 is Cbm, OH-Cbm, CH 3 -Cbm, OCH 3 -Cbm or OEt-Cbm.