17-chlorophenyl trinor Prostaglandin F2α ethyl amide

Prostaglandin F2α (PGF2α) drives luteolysis and smooth muscle contraction by activating the FP receptor. In addition, PGF2α can activate the PGE2 receptor EP1, albeit at higher concentrations, evoking inflammatory effects. Replacement of the ω-terminal three carbons with a phenyl group, producing 17-phenyl PGF2α, gives a ligand with both greater affinity for FP and diminished affinity for EP1. Compounds based on this structure are effective in lowering intraocular pressure, reducing ocular hypertension and limiting the progression of glaucoma. 17-phenyl PGF2α ethyl amide (Bimatoprost) is a prodrug which, after entering the cornea, is hydrolyzed to give the corresponding free acid. 17-chlorophenyl trinor Prostaglandin F2α ethyl amide has a chlorine atom substituted into the meta position of the phenyl group of 17-phenyl PGF2α ethyl amide. The meta substitution of a halogen (fluorine) at this site on the free acid increases its affinity for the FP receptor and greatly decreases its affinity for the EP1 receptor.