6-Keto-PGE1 6-Keto-prostaglandin E1 6-Oxo-PGE1 6-Oxoprostaglandin E1 6-ketoprostaglandin E1 67786-53-2 Prost-13-en-1-oic acid, 11,15-dihydroxy-6,9-dioxo-, (11alpha,13E,15S)-