A common metabolic pathway for several prostaglandins (PGs), including PGD2, involves the reduction of the double bond between C-13 and C-14 and oxidation of the hydroxyl group at C-15, producing 13,14-dihydro-15-keto PGs. The removal of four carbons at the α-terminus and oxidation of the terminal ω-carbon produces the abundant urinary metabolites, including tetranor-PGDM. 13,14-dihydro-15-keto-tetranor PGD2 is a potential metabolite of PGD2. It would be produced from the known metabolite 13,14-dihydro-15-keto PGD2 , which is a known agonist for the CRTH2/DP2 receptor.
