1-(4-Aminobenzyl)- and 1-(4-aminophenyl)isoquinoline derivatives: synthesis and evaluation as potential irreversible cyclic nucleotide phosphodiesterase inhibitors

In an effort to increase the specificity of the potent phosphodiesterase inhibitor papaverine, we synthesized two series of novel 1-(4-aminobenzyl)- and 1-(4-aminophenyl)isoquinoline derivatives, incorporating alkylating moieties on the amine substituents. These compounds were evaluated for their inhibitory action on phosphodiesterase preparations from bovine heart and rat cerebral cortex. Studies were also conducted to determine whether these compounds were reacting with the enzymes in an irreversible manner. The compounds were potent inhibitors of the phosphodiesterases; however, no evidence was found for an irreversible inhibition.