PDE1 inhibitors: a review of the recent patent literature (2008-present).

Introduction: PDE1 has been demonstrated to be a potential drug target for a variety of diseases, such as Alzheimer's disease and cardiovascular disease. In the past decades, numerous PDE1 inhibitors with structural diversities have been developed and patented by pharmaceutical companies, providing drug candidates for exploring novel disease indications of PDE1.

Area Covered: This review aims to provide an overview of PDE1 inhibitors reported in patents from 2008 to present.

Expert Opinion: Among current PDE1 inhibitors, only a few of them showed high selectivity over other PDEs, which might cause severe side effects in the clinic. The development of highly selective PDE1 inhibitors is still the 'top priority' in the following research. The selective recognition mechanism of PDE1 with inhibitors should be further elucidated by X-ray crystallography in order to provide evidence for the rational design of selective PDE1 inhibitors. In addition, PDE1 inhibitors should be applied to different clinical indications beyond CNS diseases.