Structure−Activity Relationship Studies on 1-[2-(4-Phenylphenoxy)ethyl]pyrrolidine (SC-22716), a Potent Inhibitor of Leukotriene A4 (LTA4) Hydrolase

Leukotriene B4 (LTB4) is a pro-inflammatory mediator that has been implicated in the pathogenesis of a number of diseases including inflammatory bowel disease (IBD) and psoriasis. Since the action of LTA4 hydrolase is the rate-limiting step for LTB4 production, this enzyme represents an attractive pharmacological target for the suppression of LTB4 production. From an in-house screening program, SC-22716 (1, 1-[2-(4-phenylphenoxy)ethyl]pyrrolidine) was identified as a potent inhibitor of LTA4 hydrolase. Structure−activity relationship (SAR) studies around this structural class resulted in the identification of a number of novel, potent inhibitors of LTA4 hydrolase, several of which demonstrated good oral activity in a mouse ex vivo whole blood assay.