Synthesis of N-terminal substituted anthranilic acid dimer derivatives for evaluation on CCK receptors

A series of new N-substituted anthranilic acid dimer derivatives having a C-terminal Phe residue was synthesized and evaluated for their affinity for CCK receptors. These compounds resulted from a blended approach based firstly on the use of an alternative substructure embedded within asperlicin and secondly on the derivatization of this template with substituents chosen considering the C-terminal primary structure of the endogenous ligand. Although these compounds exhibited a regnylogical-type organization similar to that of CCK-4, they are characterized by about 1000-fold greater affinity for CCK-A receptor than the C-terminal tetrapeptide.