19(R)-hydroxy Prostaglandin E1

19(R)-hydroxy Prostaglandin E₁ is the major prostaglandin found in the semen of primates, and is derived from PGE₁. This compound has been shown to be an agonist for the EP₁ (320 nM) and EP3 (80 nM) receptor subtypes, which leads to contraction of smooth muscle. The fact that prostaglandin metabolites show biological effects different from their parent compounds illustrates one aspect of the complicated physiological functions of these diverse regulators. The use of prostaglandin analogues and metabolic derivatives is integral for structure-activity studies used in the deconvolution of these complex biochemical pathways.