Investigation of a Bicyclo[1.1.1]pentane as a Phenyl Replacement within an LpPLA₂ Inhibitor

We describe the incorporation of a bicyclo[1.1.1]­pentane moiety within two known LpPLA₂ inhibitors to act as bioisosteric phenyl replacements. An efficient synthesis to the target compounds was enabled with a dichlorocarbene insertion into a bicyclo[1.1.0]­butane system being the key transformation. Potency, physicochemical, and X-ray crystallographic data were obtained to compare the known inhibitors to their bioisosteric counterparts, which showed the isostere was well tolerated and positively impacted on the physicochemical profile

Fragment-Based Approach to the Development of an Orally Bioavailable Lactam Inhibitor of Lipoprotein-Associated Phospholipase A2 (Lp-PLA₂)

Lp-PLA₂ has been explored as a target for a number of inflammation associated diseases, including cardiovascular disease and dementia. This article describes the discovery of a new fragment derived chemotype that interacts with the active site of Lp-PLA₂. The starting fragment hit was discovered through an X-ray fragment screen and showed no activity in the bioassay (IC₅₀ > 1 mM). The fragment hit was optimized using a variety of structure-based drug design techniques, including virtual screening, fragment merging, and improvement of shape complementarity. A novel series of Lp-PLA₂ inhibitors was generated with low lipophilicity and a promising pharmacokinetic profile