15-keto prostaglandin a-1

Prostaglandin A1 (PGA1) was first isolated as a dehydration product of the PGE1 compounds found in human semen. 15-keto PGA1 is a metabolite of PGA1, produced by 15-hydroxy PG dehydrogenase. It can be produced from PGA1 in pig lung, trachea, aorta, and pulmonary artery tissue preparations. 15-keto PGA1, given at a concentration of 6 μM, causes vasoconstriction of rabbit lung that is comparable to that induced by angiotensin II.

8-iso-15-keto Prostaglandin F2α (8-iso-15-keto PGF2α) is a metabolite of the isoprostane 8-iso PGF2α in rabbits, monkeys, and humans. 8-iso PGF2α is a prostaglandin-like product of non-specific lipid peroxidation. In humans and monkeys, exogenously infused 8-iso PGF2α is converted to metabolites with 2 or 4 carbon atoms removed from the top side chain by β-oxidation, with a similar pattern observed in tritiated 8-iso PGF2α-infused rabbits. Early in the infusion (within 1-2 minutes), 8-iso-15-keto PGF2α is a major component of the metabolite profile, primarily comprising unmetabolized 8-iso PGF2α. 8-iso-15-keto PGF2α is a vasoconstrictor when tested on the rat isolated thoracic aorta, acting via the TP (thromboxane) receptor.

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.

Latanoprost is an F-series prostaglandin (PG) analog which has been approved for use as an ocular hypotensive drug. Oxidation of the C-15 hydroxyl group without isopropyl ester hydrolysis produces 15-keto latanoprost. 15-keto Latanoprost is a potential metabolite of latanoprost when administered to animals. 15-keto Latanoprost is also one of the common minor impurities found in commercial preparations of the bulk drug compound. Although much less potent that the parent compound latanoprost, 15-keto latanoprost still retains the ability to produce a small but measurable decrease (1 mm Hg) in the intraocular pressure of normal cynomolgus monkeys when administered at a dose of 1 μg/eye. 15-keto Latanoprost is also a miotic in the normal cat eye, causing an 8 mm reduction in pupillary diameter at 5 μg/eye. Again, this is not as potent as many other F-type PGs; for example, PGF2α will produce this degree of miosis at a dose of less than 1 μg/eye. Products of β-oxidation account for most of the metabolites of latanoprost recovered in plasma and urine. However, 15-keto latanoprost is a minor metabolite, and one which could be enhanced in situations where β-oxidation is reduced.

15-keto Latanoprost is a potential metabolite of latanoprost when administered to animals and is a common minor impurity in commercial preparations of the bulk drug compound. Although much less potent than latanoprost, 15-keto Latanoprost can still produce a small but measurable decrease (1 mm Hg) in intraocular pressure in normal cynomolgus monkeys at a dose of 1 μg/eye. It also acts as a miotic in normal cats, causing an 8 mm Hg reduction in pupillary diameter at 5 μg/eye, though it is not as potent as many other F-type prostaglandins, such as prostaglandin F2α, which achieves the same effect at less than 1 μg/eye.

Bimatoprost is an F-series prostaglandin (PG) analog approved for use as an ocular hypotensive drug. Oxidation of the C-15 hydroxyl group and amide hydrolysis of Bimatoprost produces 15-keto-17-phenyl trinor PGF2α, a potential metabolite when administered to animals. 15-keto PG analogs can be minor impurities in commercial preparations of corresponding bulk drug compounds. Although much less potent than the parent compound, 15-keto PGs can still produce a small but measurable decrease (1 mm Hg) in intraocular pressure of normal cynomolgus monkeys at a dose of 1 μg/eye. 15-keto Latanoprost (15-keto-17-phenyl-13,14-dihydro trinor PGF2α isopropyl ester) acts as a miotic in normal cat eyes, causing an 8 mm reduction in pupillary diameter at 5 μg/eye. This is less potent compared to many other F-type PGs; for example, PGF2α induces similar miosis at less than 1 μg/eye.

13,14-Dihydro-15-keto prostaglandin D2 (DK-PGD2), a PGD2 metabolite formed by the 15-hydroxyl PGDH pathway, is a selective agonist for the DP2 receptor and can inhibit ion flux in canine colonic mucosa preparation [1].