Optimization of Chromeno[2,3- c]pyrrol-9(2 H)-ones as Highly Potent, Selective, and Orally Bioavailable PDE5 Inhibitors: Structure-Activity Relationship, X-ray Crystal Structure, and Pharmacodynamic Effect on Pulmonary Arterial Hypertension.
Wu D, Huang Y, Chen Y, Huang YY, Geng H, Zhang T, Zhang C, Li Z, Guo L, Chen J, Luo HB.
To further explore the structure-activity relationship around the chromeno[2,3- c]pyrrol-9(2 H)-one scaffold, 19 derivatives as inhibitors against PDE5 were discovered. The most potent inhibitor 3 has an IC50 of 0.32 nM with remarkable selectivity and druglike profile. Oral administration of 3 (1.25 mg/kg) caused comparable therapeutic effects to sildenafil (10.0 mg/kg) against pulmonary arterial hypertension. Further, different binding patterns from sildenafil were revealed in cocrystal structures, which provide structural templates for discovery of highly potent PDE5 inhibitors.