Discovery of a new class of ghrelin receptor antagonists.

A series of benzodiazepine antagonists of the human ghrelin receptor GHSR1a were synthesized and their antagonism and metabolic stability were evaluated. The potency of these analogs was determined using a functional aequorin (Euroscreen) luminescent assay measuring the intracellular Ca(2+) concentration, and their metabolic stability was measured using an in vitro rat and human S9 hepatocyte assay. These efforts led to the discovery of a potent ghrelin antagonist with good rat pharmacokinetic properties.