Somatostatin analogue compounds

1. A compound of Formula I,

wherein,

R 1 is aryl, substituted-aryl, or aryl-(lower-alkyl)-;

R 2 is lower alkyl, amino substituted lower alkyl, -carboxy-(lower-alkyl), -carbamic acid-(lower-alkyl) or -carboxy-(lower-alkyl)-aryl; and

R 3 and R 4 are independently, lower-alkyl, or lower alkyl substituted with indole;

or a pharmaceutically acceptable, ester, ether, or salt thereof.

2. The compound of claim 1 , wherein R 1 is aryl.

3. The compound of claim 1 , wherein R 1 is substituted-aryl.

4. The compound of claim 1 , wherein R 1 is -(lower-alkyl)-aryl.

5. The compound of claim 1 , wherein R 3 is lower-alkyl, or lower alkyl substituted with indole.

6. The compound of claim 1 , wherein R 4 is lower-alkyl, or lower alkyl substituted with indole.

7. A compound of Formula II,

wherein,

R 1 is lower-alkyl, substituted lower-alkyl, aryl, substituted-aryl, aryl-(lower-alkyl)-, (substituted-aryl)-(lower-alkyl)-, heteroaryl, heteroaryl-(lower-alkyl)-, substituted-heteroaryl, (substituted-heteroaryl)-(lower-alkyl)-, heterocyclic, heterocyclic-(lower-alkyl)-, substituted heterocyclic, or (substituted-heterocyclic)-(lower-alkyl)-; and

R 3 and R 4 are independently, lower-alkyl or lower alkyl substituted with indole.

8. A compound of Formula III,

wherein,

R 2 is lower alkyl, amino substituted lower alkyl, lower-alkyl carbonyl, -carboxy-(lower-alkyl), or -carboxy-(lower-alkyl)-aryl; and

R 3 and R 4 are independently, lower-alkyl or lower alkyl substituted with indole.

9. A compound of Formula IV,

wherein,

R 3 and R 4 are independently, lower-alkyl or lower alkyl substituted with indole.