Cyclic peptide compounds and methods of use

A cyclic peptide compound having the general formula (I):

• wherein:
• X3 is Cys, Glu, Asp, Lys, Orn, 2,4-Diaminobutyric Acid (Dab), 2,3-Diaminopropionic Acid (Dap), Ser, Gln, or halogenated alanine, or their corresponding enantiomeric D-amino acids;
• X13 is Cys, Glu, Asp, Lys, Orn, Dab, Dap, Ser, Gln, or halogenated alanine, or their corresponding enantiomeric D-amino acids;
• X8 is Aib;
• The symbol “” represents a chemical bond between X3 and X13, wherein the chemical bond is selected from:
• —SS—, —CH2—S—CH2—, —CO—NH—, —CO—O—, —CH2—NH—, —(CH2)n (n=2-15), or —(CH2)n-CH═CH—(CH2)n (n=2-15);
• or
• —S—(CH2)n-R1—(CH2)n-S—, wherein R1 is a hydrocarbon group, an aryl group or a heteroaryl group, n=1-3;
• Y1 is present or absent, and when present, Y1 is R2—CO—, wherein R2 is a hydrocarbon group, an aryl group, or a heteroaryl group;
• Y2 is present or absent, and when present, Y2 is a carboxy-terminal group.