PGA2 is a naturally occurring prostaglandin in gorgonian corals where it may function in self defense. It is generally not present in mammals. PGA2 has low biological potency in most bioassays, but it does show some antiviral antitumor activity.[1] At a 25 uM concentration, PGA2 blocks the cell cycle progression of NIH 3T3 cells at the G1 and G2 M phase .[2] It has also been shown to act as a vasodilator with natriuretic properties.[3]
16,16-dimethyl PGA2 is a metabolism-resistant analog of PGA2 with a prolonged in vivo half-life. It inhibits the proliferation of Sendai virus in cultured African green monkey kidney cells by >90% at a concentration of 4 μg ml. Daily infusion of 10 μg of 16,16-dimethyl PGA2 methyl ester into mice infected with influenza A virus increased survival by 40%. Similar treatment of mice inoculated with erythroleukemia cells delayed tumor growth and increased survival time.
17-phenyl trinor-13,14-dihydro Prostaglandin A2 is a synthetic analog of prostaglandin with relatively unexplored biological activity. Similarly structured, particularly in its lower side chain, to the PGF2α analog latanoprost, which is an approved glaucoma treatment, this compound presents an interesting subject for further pharmaceutical research and potential therapeutic applications.
Arbaprostil, a synthetic analog of prostaglandin E2 (PGE2) known as 15(R)-15-methyl prostaglandin E2, was developed for its cytoprotective activity. In the commercial production of bulk arbaprostil, one potential impurity is 15(R)-15-methyl Prostaglandin A2 (15(R)-15-methyl PGA2). The pharmacology and EP receptor binding affinity of 15(R)-15-methyl PGA2 have not been reported.
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)
Prostaglandin H2 (PGH2), initially isolated from the incubation of arachidonic acid with ovine seminal vesicle microsomes, acts as a potent vasoconstrictor. It serves as the precursor for all 2-series prostaglandins (PGs) and thromboxanes (TXs). Moreover, as a TP receptor agonist, PGH2 irreversibly aggregates human platelets at concentrations of 50-100 ng ml.
Prostaglandin F1α (PGF1α) is the putative metabolite of dihomo-γ-linolenic acid (DGLA) via the cyclooxygenase (COX) pathway. Both PGF1α and PGF2α have been shown to act as priming pheromones for male Atlantic salmon with a threshold concentration of 10-11 M. [1] PGF1α binds to the ovine corpus luteum FP receptor at only 8% of the relative potency of PGF2α. [2] It is only half as active as PGF2α in inducing human respiratory smooth muscle contractions in vitro. [3]
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)
The prostaglandin E receptor 4 (EP4) is one of four G protein-coupled receptors that mediate the actions of prostaglandin E2 . Binding of PGE2 to the EP4 receptor causes an increase in intracellular cyclic AMP, which plays important roles in bone formation and resorption, cancer, and atherosclerosis. KMN-80 is a substituted γ-lactam (pyrrolidinone) derivative of PGE1 that acts as a selective and potent agonist of EP4 with an IC50 value of 3 nM (IC50 = 1.4 μM for EP3 and > 10 μM for all other prostanoid receptors). In functional assays it has been shown to stimulate secreted alkaline phosphatase gene reporter activity in EP4-transfected HEK293 cells with an EC50 value of 0.19 nM, demonstrating >5,000 and 50,000-fold selectivity against EP2 and TP, respectively. KMN-80 can induce the differentiation of bone marrow stem cells from both young and aged rats into osteoblasts in vitro (EC50s = 20 and 153 nM, respectively) and exhibits favorable tolerability up to at least 10 μM, whereas the EP4 agonist L-902,688 is highly cytotoxic at similar concentrations in these cells. KMN-80 has been used to repair calvarial defects in an in vivo rat craniomaxillofacial reconstruction model (rate of reduction in defect size equivalent to BMP-2 treated rats) and to promote bone formation in a rat incisor tooth socket model.
Butaprost is a chemical compound that functions as a selective agonist for the prostaglandin E receptor (EP2). It exhibits an EC50 of 33 nM and a Ki of 2.4 μM when interacting with the murine EP2 receptor. However, Butaprost demonstrates lower activity against murine EP1, EP3, and EP4 receptors. Furthermore, it effectively attenuates fibrosis by inhibiting the TGF-β Smad2 signaling pathway [1] [2] [3].
8-iso-13,14-dihydro-15-keto Prostaglandin F2α (8-iso-13,14-dihydro-15-keto PGF2α) is a metabolite of the isoprostane, 8-isoprostane (8-iso PGF2α), in rabbits, monkeys and humans. 8-iso PGF2α is a PG-like product of non-specific lipid peroxidation. In both humans and monkeys, exogenously infused 8-isoprostane is converted primarily to metabolites having 2 or 4 carbon atoms removed from the top side chain by β-oxidation. A similar pattern is observed when tritiated 8-isoprostane is infused into rabbits. Early in the infusion (within 10 minutes) 8-iso-13,14-dihydro-15-keto PGF2α was a significant component of the metabolite profile, which was comprised mostly of dinor 8-isoprostane metabolites. 8-iso-13,14-dihydro-15-keto PGF2α weakly inhibits the U-46619 or collagen-induced aggregation of human platelets, although a number of the E-series isoprostanes are much more potent in this assay.
Pexopiprant, a potent oral antagonist of the prostaglandin D2 receptor 2 (DP2) with a K i value less than 100nM, is a valuable compound for asthma research.