15-Keto-PGE2 15-Keto-prostaglandin E2 15-Ketoprostaglandin E2 15-Oxo-PGE2 26056-55-3 26441-05-4 80424-16-4 9,15-Dioxo-11-hydroxyprosta-5,13-dienoic acid Prosta-5,13-dien-1-oic acid, 11-hydroxy-9,15-dioxo-, (5Z,11alpha,13E)-