Dihydropyrrole[2,3-d]pyridine derivatives as novel corticotropin-releasing factor-1 antagonists: mapping of the receptor binding pocket by in silico docking studies

In an effort to discover novel CRF-1 receptor antagonists exhibiting improved physicochemical properties, a dihydropirrole[2,3]pyridine scaffold was designed and explored in terms of the SAR of the substitution at the pendent phenyl ring and the nature of the heterocyclic moieties present in the upper region of the molecule. Selective and potent compounds have been discovered endowed with reduced ClogP with respect to compounds known in the literature. Of particular relevance was the finding that the in vitro affinity of the series was maintained by reducing the overall lipophilicity. The results achieved by this exploration enabled the formulation of a novel hypothesis on the nature of the receptor binding pocket of this class of CRF-1 receptor antagonists, making use of in silico docking studies of the putative nonpeptidic antagonist binding site set up in house by homology modeling techniques.