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
HPGDS inhibitor 3 is a powerful oral compound that selectively inhibits the hematopoietic prostaglandin D synthase (H-PGDS). With an IC50 value of 9.4 nM and EC50 of 42 nM, it demonstrates high potency in peripherally restricting H-PGDS. Moreover, HPGDS inhibitor 3 exhibits excellent selectivity with no associated central nervous system toxicity. This compound also possesses favorable pharmacokinetic properties in mouse, rat, and dog models. Additionally, HPGDS inhibitor 3 displays noteworthy anti-inflammatory activity [1].
Prostaglandin D2 is synthesized by hematopoietic-type PGD-synthase (H-PGDS) in mast cells and is released in large quantities during allergic and asthmatic anaphylaxis. PGD2 is also produced in the brain by lipocalin-PGD-synthase also known as β-trace. In the brain, PGD2 produces normal physiological sleep and lowering of body temperature. Further pharmacological actions include inhibition of platelet aggregation and relaxation of vascular smooth muscle. tetranor-PGDM is a major metabolite of PGD2 that is detectable in human and mouse urine. The levels of tetranor-PGDM and 2,3-dinor-11β-PGF2α , a related PGD2 metabolite, in human urine were found to be 1.5 ± 0.3 and 0.6 ± ng mg creatinine, respectively. tetranor-PGDM was detected in murine urine at a level of 8.1 ± 1.3 ng mg creatinine.
TAS 205 is an inhibitor of hematopoietic prostaglandin D synthase (H-PGDS; IC50= 55.8 nM).1It is selective for H-PGDS over lipocalin-type PGDS (L-PGDS) at 100 μM, as well as over enzyme and receptor panels at 10 μM. TAS 205 inhibits production of prostaglandin D2induced by A23187 in KU812 human and RBL-2H3 rat basophils with IC50values of 78.3 and 181.3 nM, respectively. It inhibits ovalbumin-induced nasal lavage fluid eosinophil infiltration and late-phase nasal obstruction in an ovalbumin-sensitized guinea pig model of allergic rhinitis when administered at a dose of 30 mg kg. 1.Aoyagi, H., Kajiwara, D., Tsunekuni, K., et al.Potential synergistic effects of novel hematopoietic prostaglandin D synthase inhibitor TAS-205 and different types of anti-allergic medicine on nasal obstruction in a Guinea pig model of experimental allergic rhinitisEur. J. Pharmacol.875173030(2020)