In previous studies, we have described the discovery and structureactivity relationships associated with a series of prostacyclin (PGIz) mimetics that are structurally quite different to the endogenous prostanoid.'" This effort was initiated following the discovery that the triphenylated imidazole derivative octimibate acts as a partial agonist at the prostacyclin re~ eptor.~~~ This new class of PGIz mimetic, characterized by architectural simplicity and ...