Compounds, methods and formulations for the oral delivery of a glucagon-like peptide (GLP)-1 compound or a melanocortin-4 receptor (MC4) agonist peptide

1. A compound of

wherein: R 1 is selected from OH or NH 2 and is at the ortho-position relative to heterocycle X;

R 2 is selected from OCH 3 and H and is at the para-position relative to heterocycle X;

R 3 is H;

X a is a 5 membered aromatic heterocycle that is optionally substituted with C 1 -C 4 alkyl; wherein said heterocycle contains at least two or three heteroatoms selected from N, S and O wherein at least one heteroatom must be N and wherein said heterocycle may not be 1,3,4-oxadiazole; and

n is 2, 3, 4, 5, 6, or 7;

or a pharmaceutical salt thereof.

2. A compound which is:

or a pharmaceutical salt thereof.

3. A compound which is:

or a pharmaceutical salt thereof.

4. A compound which is:

or a pharmaceutical salt thereof.

5. A compound which is:

or a pharmaceutical salt thereof.

6. A compound which is:

or a pharmaceutical salt thereof.

7. A pharmaceutical composition comprising:

a) the compound of claim 1 or a pharmaceutical salt thereof; and

b) a GLP-1 compound.

8. The composition of claim 7 , wherein the GLP-1 compound is Val 8 -Glu 22 -GLP-1 (7-37)OH.

9. A pharmaceutical composition comprising:

a) the compound of claim 1 or a pharmaceutical salt thereof; and

b) an MC4 agonist peptide.

10. The composition of claim 9 wherein the MC4 agonist is selected from the group consisting of:

Ac-Arg-cyclo[Cys-Glu-His-D-Phe-Arg-Trp-Cys]-NH 2 ;

Ac-cyclo[hCys-His-D-Phe-Arg-Trp-Cys]-NH 2 ;

Ac-cyclo[hCys-His-D-Phe-Arg-Trp-penicillamine]-NH 2 ; and

N-cyclohexanecarbonyl-cyclo[hCys-His-D-Phe-Arg-Trp-penicillamine]-NH 2 .