Prostaglandin D1 (PGD1) is the theoretical D-series metabolite of dihomo-γ-linolenic acid (DGLA), but to date it has not been isolated as a natural product. It is an inhibitor of ADP-induced platelet aggregation in humans with an IC50 value of 320 ng/ml, about 1/10 as potent as PGD2. 13,14-dihydro-15-keto Prostaglandin D1 (13,14-dihydro-15-keto PGD1) is the theoretical metabolite of PGD1 via the 15-hydroxy PG dehydrogenase metabolic pathway. No biological studies for this compound have been reported.
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
AMK is an active metabolite of the neurohormone melatonin .1,2,3,4It is formed from melatoninviathe metabolic intermediate AFMK that is then deformylated by catalase or formamidase.5,6AMK scavenges singlet oxygenin vitrowhen used at a concentration of 200 μM.1It inhibits the epinephrine- and arachidonic acid-induced production of prostaglandin E2and PGD2in ovine seminal vesicle microsomes in a concentration- and time-dependent manner, as well as LPS-induced increases in COX-2 levels in RAW 264.7 macrophages when used at a concentration of 500 μM.2,3AMK (20 mg kg) decreases MPTP-induced increases in lipid peroxidation in the cytosol and mitochondria from substantia nigra and striatum in a mouse model of MPTP-induced Parkinson’s disease.4 1.Schaefer, M., and Hardeland, R.The melatonin metabolite N1-acetyl-5-methoxykynuramine is a potent singlet oxygen scavengerJ. Pineal Res.46(1)49-52(2009) 2.Kelly, R.W., Amato, F., and Seamark, R.F.N-acetyl-5-methoxy kynurenamine, a brain metabolite of melatonin, is a potent inhibitor of prostaglandin biosynthesisBiochem. Biophys. Res. Commun.121(1)372-379(1984) 3.Mayo, J.C., Sainz, R.M., Tan, D.-X., et al.Anti-inflammatory actions of melatonin and its metabolites, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5-methoxykynuramine (AMK), in macrophagesJ. Neuroimmunol.165(1-2)139-149(2005) 4.Tapias, V., Escames, G., López, L.C., et al.Melatonin and its brain metabolite N1-acetyl-5-methoxykynuramine prevent mitochondrial nitric oxide synthase induction in parkinsonian miceJ. Neurosci. Res.87(13)3002-3010(2009) 5.Tan, D.-X., Manchester, L.C., Reiter, R.J., et al.Melatonin directly scavenges hydrogen peroxide: A potentially new metabolic pathway of melatonin biotransformationFree Radic. Biol. Med.29(11)1177-1185(2000) 6.Hirata, F., Hayaishi, O., Tokuyama, T., et al.In vitro and in vivo formation of two new metabolites of melatoninJ. Biol. Chem.249(4)1311-1313(1974)
O-Desmethyl-N-deschlorobenzoyl indomethacin is a metabolite of the non-steroidal anti-inflammatory drug (NSAID) and COX inhibitor indomethacin .1It is formed from indomethacin in isolated rabbit hepatocytes. O-Desmethyl-N-deschlorobenzoyl indomethacin (600 μM) decreases the viability of HL-60 leukemia cells when cultured with glucose oxidase.2It has also been used in the synthesis of prostaglandin D2receptor antagonists.3 1.Evans, M.A., Papazafiratou, C., Bhat, R., et al.Indomethacin metabolism in isolated neonatal and fetal rabbit hepatocytesPediatr. Res.15(11)1406-1410(1981) 2.Morgan, A.G.M., Babu, D., Michail, K., et al.An evaluation of myeloperoxidase-mediated bio-activation of NSAIDs in promyelocytic leukemia (HL-60) cells for potential cytotoxic selectivityToxicol. Lett.28048-56(2017) 3.Torisu, K., Kobayashi, K., Iwahashi, M., et al.Discovery of new chemical leads for prostaglandin D2 receptor antagonistsBioorg. Med. Chem. Lett.14(17)4557-4562(2004)
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)
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].
Dehydroglyasperin D exhibits anticancer, anti-inflammatory, anti-obesity, antioxidant and anti-aldose reductase effects, it inhibits the proliferation of HT-29 human colorectal cancer cells through direct interaction with phosphatidylinositol 3-kinase; it also mediates suppression of both COX-2 expression and the MLK3 signalling pathway through direct binding and inhibition of MLK3. Dehydroglyasperin D shows strong ferric reducing activities and effectively scavenged DPPH, ABTS(+), and singlet oxygen radicals.