Prostaglandin E2 (PGE2) isopropyl ester is a more lipophilic form of the free acid, PGE2. PG esters have enhanced lipid solubility compared to their parent compounds. They are generally hydrolyzed to the free acid by endogenous esterases upon in vivo administration, making the esters useful prodrugs. In general, the C-1 esters of PGs show greatly diminished receptor activity in vitro compared to the parent free acids.

Enzymatically-derived prostaglandin E2 (PGE2) is an optically pure compound whereas PGE2 derived from the free radical-catalyzed peroxidation of arachidonate is a racemic mixture. Ent-PGE2 is the opposite enantiomer of PGE2. Significant amounts of racemic PGE2 (rac-PGE2) are generated in vitro and in vivo in settings of oxidative stress via the isoprostane pathway. A proposed mechanism for the formation of rac-PGE2 involves the base catalyzed equilibration from 15-E2t-isoprostane (8-iso-PGE2), generated from the 15-H2t-isoprostane endoperoxide.

11-deoxy Prostaglandin E2 (11-deoxy PGE2) is a stable, synthetic analog of PGE2 . In contrast to PGE2 which has bronchodilation effects, 11-deoxy PGE2 is a powerful bronchoconstrictor and contracts human respiratory tract smooth muscle with potencies ranging from 5 to 30 times higher than PGF2α .

9-deoxy-9-methylene Prostaglandin E2 (9-deoxy-9-methylene PGE2) is a stable, isosteric analog of PGE2 . 9-deoxy-9-methylene PGE2 retains the biological profile of PGE2 with fewer side effects. In the rat 9-deoxy-9-methylene PGE2 is equipotent to PGE2 in decreasing blood pressure. It also stimulates the gerbil colon and primate uterus at the same potency as PGE2.

1a,1b-dihomo Prostaglandin E2 (PGE2) is a rare polyunsaturated fatty acid first identified in extracts of sheep vesicular gland microsomes, known to contain COX, incubated with adrenic acid . 1a,1b-dihomo PGE2 has also been identified in conditioned media of RAW 264.7 macrophages stimulated with endotoxin and arachidonic acid . This product is thought to be produced by elongation of AA to adrenic acid, which is then metabolized sequentially by COX and PGE synthase.

Prostaglandin E2 (PGE2) inhibitor 3 is a selective inhibitor targeting microsomal prostaglandin E synthase-1 (mPGES-1; IC50 = 0.2 µM), demonstrating greater selectivity for mPGES-1 over COX-1, COX-2, 5-lipoxygenase (5-LO), and soluble epoxide hydrolase (sEH) in assays at 10 µM. This compound effectively reduces IL-1β-induced PGE2 production in A549 cells and decreases LPS-induced IL-6 and PGE2 in J774A.1 macrophages at concentrations of 10 and 1 µM, respectively. Additionally, it blocks the production of 5-LO-derived products, including leukotriene B4 (LTB4) and 5-H(p)ETE, in response to calcium ionophore A23187 alone or combined with arachidonic acid, with IC50 values of 4.9 and 5.2 µM, respectively. When administered in vivo at doses of 10 mg/kg, PGE2 inhibitor 3 effectively prevents leukocyte infiltration in a mouse model of zymosan-induced peritonitis.

17-phenyl trinor PGE2 ethyl amide is derived from 17-phenyl trinor PGE2, a synthetic analog of PGE2 that acts as an agonist of EP1 and EP3 receptors in mice (Ki = 14 and 3.7 nM, respectively) and EP1, EP3, and EP4 in rats (Ki = 25, 4.3, and 54 nM, respectively). 17-phenyl trinor PGE2 causes contraction of guinea pig ileum at a concentration of 11 μM and is 4.4 times more potent than PGE2 as an antifertility agent in hamsters. Modification of the C-1 carboxyl group to an ethyl amide serves to increase lipid solubility, thereby improving uptake into tissues and further lowering the effective concentration. Ethyl amide groups are then removed by amidases, regenerating the active free acid.

8-iso PGE2 isopropyl ester is a more lipophilic form of the free acid, 8-iso PGE2. Prostaglandin esters have enhanced lipid solubility compared to their parent compounds. They are generally hydrolyzed to the free acid upon in vivo administration, making the esters useful prodrugs. In general, the C-1 esters of prostaglandins show greatly diminished agonist activity in vitro compared to the parent free acids.

11-Deoxy-16,16-dimethyl Prostaglandin E2 (11-deoxy-16,16-dimethyl PGE2) is a stable synthetic analog of Prostaglandin E2 (PGE2), acting as an agonist for both EP2 and EP3 receptors. It effectively inhibits gastric acid secretion and ulcer formation in rats, with ED50 values of 1 mg/kg and 0.021 mg/kg, respectively. This compound is also 900 times more potent than Prostaglandin F2α (PGF2α) in inducing contraction of human respiratory tract smooth muscle in vitro.

9-deoxy-9-methylene-16,16-dimethyl Prostaglandin E2 (Meteneprost) is a potent analog of prostaglandin E2 with an extended half-life in vivo. In combination with various other prostaglandin derivatives, it results in the termination of first trimester pregnancy in monkeys. A single intramuscular injection containing 0.5 mg of meteneprost and 7.5 mg of 17-phenyl trinor PGF1α is very effective in terminating early pregnancy. This prostaglandin mixture is ineffective on monkeys in their third trimester of pregnancy. Meteneprost, when compared to PGE2 and PGF1α, in monkey and rat, does not result in unwanted side effects such as fever or gastrointestinal problems.

20-hydroxy Prostaglandin E2 (20-hydroxy PGE2) is a product of cytochrome P450 metabolism of PGE2 . ω-Oxidation at C-20 followed by β-oxidation and the loss of up to four carbons from the lower side chain is a prominent metabolic pathway for PGE2. 20-hydroxy PGE2 is the putative first intermediate in this chain of chemical transformations.

19(R)-hydroxy Prostaglandin E2 (19(R)-hydroxy PGE2), present in the semen of primates, including humans, acts as a potent smooth muscle relaxant and is a selective agonist for the EP2 receptor. It exhibits an EC50 value of 200 nM for relaxing cat tracheal rings that express EP2 receptors.

20-Ethyl Prostaglandin E2 (20-ethyl PGE2) is an analog of Prostaglandin E2 (PGE2) characterized by an extended ω-chain due to two additional methylene carbon atoms. Compared to unoprostone, a clinically approved glaucoma medication and the only extensively studied prostaglandin analog sharing this structural modification, 20-ethyl PGE2 maintains the natural 15(S) allylic hydroxyl in its lower side chain, potentially enhancing its effectiveness. Unoprostone, despite being an F-series prostaglandin, exhibits reduced affinity for FP receptors because of its lower side chain modifications (13,14-dihydro-15-keto), which diminishes its medicinal potency. Notably, 20-ethyl PGE2's efficacy relative to unoprostone and its interaction with EP or other prostanoid receptors remains unconfirmed due to the lack of published ligand binding assays. E-type prostaglandins, including 20-ethyl PGE2, are broadly acknowledged for their inflammatory, cytoprotective, and diverse biological activities.

5-trans-Prostaglandin E2 accelerates fibrinolysis by enhancing plasminogen activation mediated by tissue-type plasminogen activator. It also inhibits platelet aggregation in human PRP.

8-iso Prostaglandin E2 (8-iso PGE2) is one of several isoprostanes produced from polyunsaturated fatty acids during lipid peroxidation. 8-iso-16-cyclohexyl-tetranor PGE2 is a synthetic analog of 8-iso PGE2. There are no published studies on the pharmacological properties of 8-iso-16-cyclohexyl-tetranor PGE2.

Prostaglandin E2 Serinol Amide acts as a weak inhibitor against the hydrolysis of [3H]2-oleoylglycerol, but it is non-hydrolyzable and cannot produce PGE2. Consequently, it is unable to inhibit leukotriene B4 biosynthesis, superoxide production, migration, and the release of antimicrobial peptides [1].

16-phenoxy tetranor PGE2, the free acid form of sulprostone, results from the hydrolysis of the methylsulfonamide bond. It is identified as a minor metabolite in human plasma following the parenteral administration of sulprostone.

13,14-dihydro-15-keto Prostaglandin E2 (13,14-dihydro-15-keto PGE2) serves as the predominant metabolite of PGE2 in plasma, created through a 15-keto PGE2 intermediate by the action of 15-oxo-PG Δ13 reductase. Unlike its precursor PGE2, this compound exhibits poor binding affinity towards EP2 and EP4 PGE2 receptors (Ki values of 12 and 57 µM, respectively) in CHO cells and fails to stimulate adenylate cyclase activity therein (EC50s >18 and >38 µM, respectively). Concentrations of 13,14-dihydro-15-keto PGE2 are notably higher in the plasma of pregnant women during their third trimester and at labor and delivery stages, whereas its levels are found to be reduced in the tumor tissues of patients with non-small cell lung cancer (NSCLC) compared to adjacent healthy tissue.

17-Phenyl trinor Prostaglandin E2 (17-phenyl trinor PGE2) is a synthetic analog of PGE2, functioning as an agonist at the EP1 and EP3 receptors. It induces contraction of the guinea pig ileum at a 11 µM concentration and displays slightly less potency than PGE2 in stimulating the gerbil colon and rat uterus. Notably, with an ED50 value of 350 µg/kg, 17-phenyl trinor PGE2 exhibits 4.4 times greater antifertility efficacy in hamsters compared to PGE2.

15-keto-Prostaglandin E2, an endogenous metabolite, inhibits STAT3 activation through binding to Cys259 and regulates breast cancer cell growth and progression. Additionally, it binds and stabilizes the EP2 and EP4 receptors, activates PPAR-γ, and promotes fungal growth [1] [2] [3].

8-iso PGE2 is one of several isoprostanes produced from arachidonic acid during lipid peroxidation. It is a potent renal vasoconstrictor in the rat. 8-iso PGE2 inhibits U-46619 or I-BOP-induced platelet aggregation with IC50 values of 0.5 and 5 μM, respectively. When infused into the renal artery of the rat at a concentration of 4 μg/kg/min, 8-iso PGE2 decreases the GFR and renal plasma flow by 80% without affecting blood pressure.

Prostaglandin E2 Ethanolamide (PGE 2 -EA), an analog of PGE2, is enzymatically synthesized through COX-2 oxygenation of endocannabinoids. It has the potential to modulate the production of the proinflammatory cytokine TNF-α in human blood and monocytic cells [1] [2].

15(R)-Prostaglandin E2, the C-15 epimer of the more physiologically abundant 15(S)-PGE2 (sc-201225) isomer, is produced mainly from arachidonic acid (sc-200770) via the action of COX and PGES enzymes. Present in nearly all cell types, PGE2 interacts with four distinct receptors, EP1 to EP4, leading to a wide range of biological effects. However, 15(R)-Prostaglandin E2 exhibits significantly lower efficacy in most biological assays compared to its 15(S) counterpart. Notably, acid catalyzed epimerization can transform 15(R)-Prostaglandin E2 into the more active 15(S)-Prostaglandin E2 form.

Prostaglandin E2-1-glyceryl ester, a member of the Prostaglandin Glycerol Ester family, serves as an endocannabinoid ligand targeting the CB1 receptor. This compound triggers a swift and transient surge in intracellular free calcium levels [1] [2].

Prostaglandin E1 (PGE1), though not predominantly found in nature, plays a significant role in clinical treatments, addressing conditions such as peripheral occlusive vascular disease, erectile dysfunction, and neonatal cardiology issues. The metabolism of PGE1 primarily begins with the oxidation at C-15, producing 13,14-dihydro-15-keto PGE1 as its major metabolite. Alternatively, inhibiting this pathway or overwhelming it with too much PGE1 could potentially enhance the production of 2,3-dinor metabolites, like 2,3-dinor PGE1, though their biological activities remain unreported. Cayman Chemical stands out as a prominent provider of prostaglandins and their metabolites, uniquely manufacturing 2,3-dinor PGE1.

Prostaglandin E2-biotin, an analog of prostaglandin, is utilized in the research of Nurr1-related diseases, including cancer and autoimmune diseases [1].

11β-PGE2 is the C-11 epimer of PGE2. It is a moderate inhibitor of PGE2 binding to rat hypothalamic membranes with a Ki value of 53 nM.[1] 11β-PGE2 also stimulates bone resorption in rats at concentrations of 10-8 to 10-6 M which is similar to PGE2.2 11β-PGE2 inhibits PGE2 binding to the prostaglandin transporter protein with a Ki of 56 nM.[3] .

15(S)-15-methyl PGE2 is a potent, metabolically stable analog of PGE2. It is a potent gastric antisecretory and antiulcer compound. 15(S)-15-methyl PGE2 binds to human myometrium with twice the affinity of PGE2 and is ten times more potent than PGE1 in contracting uterine smooth muscle.

1. Tussilagone inhibits dendritic cell function through the induction of heme oxygenase-1. 2. Tussilagone has anti-cancer activity, might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer. 3. Tussilagone has anti

2-(E-2-decenoylamino)ethyl 2-(cyclohexylethyl) sulfide is a compound known to inhibit stress-induced ulcers, effectively maintaining the levels of phospholipase A2 and prostaglandin E2 in rats subjected to water immersion-restrained stress-induced ulceration.

HPGDS inhibitor 2 (GSK-2894631A) is a potent, selective hematopoietic prostaglandin D synthase (h-pgds) inhibitor, IC50 = 9.9 nm.

Epibetulinic acid has anti-inflammatory activity, it exhibits potent inhibitory effects on NO and prostaglandin E(2) production in mouse macrophages (RAW 264.7) stimulated with bacterial endotoxin.

Latanoprost is an F-series prostaglandin analog which has been approved for use as an ocular hypotensive drug. 5-trans Latanoprost is an isomer of latanoprost wherein the double bond between carbons 5 and 6 has been changed from cis (Z) to trans (E). The trans isomer of latanoprost occurs as an impurity of between 2-5% in most commercial preparations of the bulk drug product. The present compound was prepared primarily as an analytical standard for detection and quantitation of this impurity. From what can be inferred from the study of other trans isomers of F-type prostaglandins, 5-trans latanoprost's biological activity is likely to be similar to that of the cis isomer. However, there are no specific published reports on the biological activity, and on the intraocular hypotensive activity in particular, of 5-trans latanoprost.

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.

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].

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.

8(E),10(E),12(Z)-Octadecatrienoic acid is a conjugated polyunsaturated fatty acid (PUFA) that has been found inC. officinalisseed oil and has anticancer activity.1,2,3It inhibits the growth of Caco-2 cells when used at concentrations ranging from 10 to 50 μM.28(E),10(E),12(Z)-Octadecatrienoic acid (10 μM) induces formation of thiobarbituric acid reactive substances (TBARS) and apoptosis in DLD-1 colorectal adenocarcinoma cells.3It also inhibits prostaglandin biosynthesis in sheep vesicular gland microsomes (IC50= 31 μM).4 1.Crombie, L., and Holloway, S.J.The biosynthesis of calendic acid, octadeca-(8E,10E, 12Z)-trienoic, acid, by developing marigold seeds: origins of (E,E,Z) and (Z,E,Z) conjugated triene acids in higher plantsJ. Chem. Soc. Perk. T. 12425-2434(1985) 2.Yasui, Y., Hosokawa, M., Kohno, H., et al.Growth inhibition and apoptosis induction by all-trans-conjugated linolenic acids on human colon cancer cellsAnticancer Res.26(3A)1855-1860(2006) 3.Shinohara, N., Ito, J., Tsuduki, T., et al.Jacaric acid, a linolenic acid isomer with a conjugated triene system, reduces stearoyl-CoA desaturase expression in liver of miceJ. Oleo Sci.61(8)433-441(2012) 4.Nugteren, D.H., and Christ-Hazelhof, E.Naturally occurring conjugated octadecatrienoic acids are strong inhibitors of prostaglandin biosynthesisProstaglandins33(3)403-417(1987)

AF3442 is a potent and selective mPGES-1 inhibitor (microsomal prostaglandin (PG) E synthase-1). AF3442 caused a concentration-dependent inhibition of PGE(2) in human recombinant mPGES-1 with an IC(50) of 0.06microM. AF3442 is a selective mPGES-1 inhibitor which reduced monocyte PGE(2) generation also in the presence of plasma proteins. Pharmacological inhibition of mPGES-1 did not translate into redirection of PGH(2) metabolism towards other terminal PG synthases in monocytes. The functional relevance of this observation deserves to be investigated in vivo.

2,5-dimethyl Celecoxib is a derivative of celecoxib that does not inhibit COX-2 (IC50 = >100 μM).1 It does inhibit microsomal prostaglandin E synthase-1 (mPGES-1) in HeLa cells (IC50 = 15.6 μM) and reduces prostaglandin E2 production in HeLa, A549, and HCA-7 cells (IC50s = 0.64, 0.83, and 3.08 μM, respectively).2 It inhibits proliferation of drug-sensitive RPMI8226 and multidrug-resistant 8226/Dox40 multiple myeloma cells, as well as increases the rate of apoptosis when used at concentrations of 20 and 30 μM.3 2,5-dimethyl Celecoxib reduces the expression of survivin, cyclin A, cyclin B, MEK1, and MEK2 in 8226/Dox40 cells. The antiproliferative effect of 2,5-dimethyl celecoxib is independent of mPGES-1 inhibition.2References1. Zhu, J., Song, X., Lin, H.-P., et al. Using cyclooxygenase-2 inhibitors as molecular platforms to develop a new class of apoptosis-inducing agents. J. Natl. Cancer Inst. 94(23), 1745-1757 (2002).2. Wobst, I., Schiffmann, S., Birod, K., et al. Dimethylcelecoxib inhibits prostaglandin E2 production. Biochem. Pharmacol. 76(1), 62-69 (2008).3. Kardosh, A., Soriano, N., Liu, Y.-T., et al. Multitarget inhibition of drug-resistant multiple myeloma cell lines by dimethyl-celecoxib (DMC), a non-COX-2 inhibitory analog of celecoxib. Blood 106(13), 4330-4338 (2005). 2,5-dimethyl Celecoxib is a derivative of celecoxib that does not inhibit COX-2 (IC50 = >100 μM).1 It does inhibit microsomal prostaglandin E synthase-1 (mPGES-1) in HeLa cells (IC50 = 15.6 μM) and reduces prostaglandin E2 production in HeLa, A549, and HCA-7 cells (IC50s = 0.64, 0.83, and 3.08 μM, respectively).2 It inhibits proliferation of drug-sensitive RPMI8226 and multidrug-resistant 8226/Dox40 multiple myeloma cells, as well as increases the rate of apoptosis when used at concentrations of 20 and 30 μM.3 2,5-dimethyl Celecoxib reduces the expression of survivin, cyclin A, cyclin B, MEK1, and MEK2 in 8226/Dox40 cells. The antiproliferative effect of 2,5-dimethyl celecoxib is independent of mPGES-1 inhibition.2 References1. Zhu, J., Song, X., Lin, H.-P., et al. Using cyclooxygenase-2 inhibitors as molecular platforms to develop a new class of apoptosis-inducing agents. J. Natl. Cancer Inst. 94(23), 1745-1757 (2002).2. Wobst, I., Schiffmann, S., Birod, K., et al. Dimethylcelecoxib inhibits prostaglandin E2 production. Biochem. Pharmacol. 76(1), 62-69 (2008).3. Kardosh, A., Soriano, N., Liu, Y.-T., et al. Multitarget inhibition of drug-resistant multiple myeloma cell lines by dimethyl-celecoxib (DMC), a non-COX-2 inhibitory analog of celecoxib. Blood 106(13), 4330-4338 (2005).

GW833972 is a CB2 Agonist. GW 833972A inhibited capsaicin-induced depolarization of the human and guinea-pig and prostaglandin E(2) (PGE(2)) and hypertonic saline-induced depolarization of the guinea-pig isolated vagus nerve in vitro. GW 833972A also inhibited citric acid-induced cough but not plasma extravasation in the guinea-pig and this effect was blocked by a CB(2) receptor antagonist.

Prostaglandin E2 (PGE2) is a naturally occurring hormone involved in a variety of physiological processes in the body, including smooth muscle contraction and relaxation, regulation of vasodilatation and constriction, regulation of blood pressure, and inflammatory regulation.

Prostaglandin D2 (PGD2) is one of the five principal prostaglandins enzymatically derived from PGH2. It is abundantly generated in the cerebrospinal fluid (CSF) by lipocalin-type PGD synthase and in peripheral regions by myeloid cells, such as mast cells and basophils, via leukocyte-type PGD synthase. The compound 1,25-trans-PGD2 is an isomer of PGD2, characterized by the alteration of the double bond between carbons 5 and 6 from cis(Z) to trans(E). This trans isomer, found as a 2-5% impurity in most commercial PGD2 bulk drug preparations, is primarily synthesized as an analytical standard to identify and quantify this impurity. Based on existing studies of trans isomers of F-type prostaglandins, 5-trans-PGD2 likely exhibits biological activity comparable to its cis isomer, although no specific published reports confirm this for 5-trans-PGD2.

(±)-γ-Tocopherol is a form of vitamin E with antioxidant and anti-inflammatory properties. It traps and detoxifies reactive nitrogen oxide species, including nitrogen dioxide, in cell-free assays. It also reduces the synthesis of prostaglandin E2 (PGE2) induced by LPS in RAW 264.7 macrophages and by IL-1β in A549 cells. (±)-γ-Tocopherol inhibits LPS-induced nitrite release and inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells and reduces COX-2 activity in A549 cells pretreated with IL-1β. Serum levels of (±)-γ-tocopherol are decreased in patients with cardiovascular disease.

Schizandriside may have anti-inflammatory effects, it has inhibitory activities against nitric oxide and prostaglandin E(2) production in IFN-γ- and lipopolysaccharide-stimulated RAW 264.7 cells. It shows significant cytotoxicity against A549, SK-OV-3, SK

PGBx is a mixture of oligomers of PGB1 with a molecular weight of 1,000-1,500. It has antioxidant and free radical trapping activity that was first studied in isolated mitochondria.1 PGBx has anti-inflammatory and cytoprotective activity which may be attributed to inhibition of the 14 kDa sPLA2.2,3 At a dose of 1 mg/kg, PGBx significantly reduces the incidence of ulcers in rats.2References1. Polis, B.D., Polis, E., and Kwong, S. Protection and reactivation of oxidative phosphorylation in mitochondria by a stable free-radical prostaglandin polymer (PGBΧ). Proceedings of the National Academy of Sciences of the United States of America 76, 1598-1602 (1979).2. Kumashiro, R., Devlin, T.M., Kholoussy, A.M., et al. Prostaglandin BΧ in the prevention of stress ulcers in rats. International Surgery 70, 247-250 (1985).3. Franson, R.C., Rosenthal, M.D., and Regelson, W. Mechanism(s) of cytoprotective and anti-inflammatory activity of PGB1 oligomers: PGBx has potent anti-phospholipase A2 and anti-oxidant activity. Prostaglandins, Leukotrienes and Essential Fatty Acids 43, 63-70 (1991). PGBx is a mixture of oligomers of PGB1 with a molecular weight of 1,000-1,500. It has antioxidant and free radical trapping activity that was first studied in isolated mitochondria.1 PGBx has anti-inflammatory and cytoprotective activity which may be attributed to inhibition of the 14 kDa sPLA2.2,3 At a dose of 1 mg/kg, PGBx significantly reduces the incidence of ulcers in rats.2 References1. Polis, B.D., Polis, E., and Kwong, S. Protection and reactivation of oxidative phosphorylation in mitochondria by a stable free-radical prostaglandin polymer (PGBΧ). Proceedings of the National Academy of Sciences of the United States of America 76, 1598-1602 (1979).2. Kumashiro, R., Devlin, T.M., Kholoussy, A.M., et al. Prostaglandin BΧ in the prevention of stress ulcers in rats. International Surgery 70, 247-250 (1985).3. Franson, R.C., Rosenthal, M.D., and Regelson, W. Mechanism(s) of cytoprotective and anti-inflammatory activity of PGB1 oligomers: PGBx has potent anti-phospholipase A2 and anti-oxidant activity. Prostaglandins, Leukotrienes and Essential Fatty Acids 43, 63-70 (1991).