HQL-79

HQL-79 is a selective inhibtor of hematopoietic prostaglandin D (PGD) synthase, one of two synthases involved in the production of Prostaglandin D2 (PGD2) from arachidonic acid. HQL-79 selectively inhibited the activity of recombinant H-PGDS with an IC50 of 6 μM and had almost no effect on COX-1, COX-2, m-PGES, or L-PGDS up to 300 μM. HQL-79 has anti-inflammatory activity in vitro and in vivo. HQL-79 is antiallergic and anti-inflammatory. HQL-79 displays antiasthmatic activity and potent antihistaminic properties in vivo. HQL-79 is a synthetic tetrazole compound originally prepared as a possible antihistamine. Subsequent evaluation in models of allergy and asthma demonstrates the HQL-79 inhibits the synthesis of PGD2. HQL-79 is thus a likely lead compound for the preparation of potent, selective PGE synthase inhibitors.