Optimization of purine based PDE1/PDE5 inhibitors to a potent and selective PDE5 inhibitor for the treatment of male ED

Optimization of purine based PDE1/PDE5 inhibitors to a potent and selective PDE5 inhibitor for the treatment of male ED Substituted Pyrazolopyridines as Potent and Selective PDE5 Inhibitors:  Potential Agents for Treatment of Erectile Dysfunction Synthesis and phosphodiesterase 5 inhibitory activity of novel pyrido[1,2-e]purin-4(3H)-one derivatives Quinazolines as potent and highly selective PDE5 inhibitors as potential therapeutics for male erectile dysfunction N-3-Substituted Imidazoquinazolinones:  Potent and Selective PDE5 Inhibitors as Potential Agents for Treatment of Erectile Dysfunction Identification of purine inhibitors of phosphodiesterase 7 (PDE7) 2-Phenylquinazolin-4(3H)-one, a class of potent PDE5 inhibitors with high selectivity versus PDE6 Substituted Pyrazolopyridopyridazines as Orally Bioavailable Potent and Selective PDE5 Inhibitors:  Potential Agents for Treatment of Erectile Dysfunction New pyrazolo[1′,5′:1,6]pyrimido[4,5-d]pyridazin-4(3H)-ones as potent and selective PDE5 inhibitors Novel Pyrazolopyrimidopyridazinones with Potent and Selective Phosphodiesterase 5 (PDE5) Inhibitory Activity as Potential Agents for Treatment of Erectile Dysfunction