HQL-79 is a selective and orally active human hematopoietic prostaglandin D synthase (H-PGDS) inhibitor. It inhibits the synthesis of PGD2 and acts as an anti-allergic agent (Kd: 0.8 μM and IC50: 6 μM). It also shows no obvious effect on COX-1, COX-2, m-P
PF-4693627 is an effective and selective microsomal prostaglandin E synthase-1 inhibitor (IC50=3 nM). It is used for the treatment of inflammation caused by osteoarthritis (OA) and rheumatoid arthritis (RA).