(-)-7-((2R,4aR,5R,7aR)-2-(1,1-Difluoropentyl)-2-hydroxy-6-oxooctahydrocyclopenta (b)pyran-5-yl)heptanoic acid 136790-76-6 Amitiza Lubiprostone Lubiprostone [USAN] Prostan-1-oic acid, 16,16-difluoro-11-hydroxy-9,15-dioxo-, (11alpha)- RU-0211