15(R)-19(R)-Hydroxy prostaglandin E2

19(R)-Hydroxylated prostaglandins occur in μg/ml concentrations in the semen of certain mammalian species, especially primates. In the case of humans, the compounds are primarily of the PGE series, and the hydroxyl stereochemistry is 15(S),19(R).¹ 19(R)-Hydroxylated prostaglandins are also found in the seminal plasma of marsupials, where F-type compounds of the 1 and 2-series predominate.² The 15(R)-hydroxy epimer of these 19-hydroxylated prostaglandins is the inverse or “unnatural” isomer at C-15. The biological role of 19(R)-hydroxylated prostaglandins is not well established. In the E-series, 19(R)-hydroxylation has been identified with EP₂ receptor subtype selectivity.³

1. Cooper, I., and Kelly, R.W. The measurement of E and 19-hydroxy E prostaglandins in human seminal plasma Prostaglandins 10(3),507-514(1975).
2. Marley, P.B., Rodger, J.C., White, I.G., et al. 19-Hydroxylated prostaglandins in the semen of the marsupial Trichosurus vulpecula (brush-tailed possum) Comp. Biochem. Physiol. B Biochem. Mol. Biol. 70(3),619-621(1981).
3. Woodward, D.F., Protzman, C.E., Krauss, A.H.P., et al. Identification of 19(R)-OH prostaglandin E₂ as a selective prostanoid EP₂-receptor agonist Prostaglandins 46(4),371-383(1993).