The SAR of a series of beta-carboline derived type 5 phosphodiesterase inhibitors has been explored and we have discovered compounds with excellent levels of PDE5 potency and selectivity over PDE6. However, the series exhibits low levels of selectivity over PDE11, a phosphodiesterase with unknown function.
Department of Discovery Chemistry, Pfizer Global Research and Development, Sandwich Laboratories (IPC351), Ramsgate Road, Sandwich, Kent, CT13 9NJ, UK. graham_maw@sandwich.pfizer.com