15(R)-17-phenyl trinor Prostaglandin F2α

17-phenyl trinor Prostaglandin F2α N-ethyl amide (17-phenyl trinor PGF2α) is an F-series prostaglandin analog which has been approved for use as an ocular hypotensive drug, sold under the Allergan trade name 17-phenyl trinor PGF2α ethyl amide. Investigations in our lab have shown that 17-phenyl trinor PGF2α ethyl amide is converted by an amidase enzymatic activity in the human cornea to yield the corresponding free acid, with a conversion rate of about 25 µg/cornea/24 hours. The free acid, 17-phenyl trinor PGF2α, is a potent FP receptor agonist. 15(R)-17-phenyl trinor PGF2α is the 15-epi, or "unnatural" isomer of this active free acid metabolite. It has much diminished FP receptor-mediated activity, which is generally 1.5 to 2 logs less than the 15(S)-isomer. In human and animal models of glaucoma, FP receptor agonist activity corresponds very closely with intraocular hypotensive activity.