GO:0047522:   15-oxoprostaglandin 13-oxidase activity
Catalysis of the reaction: (5Z)-(15S)-11-alpha-hydroxy-9,15-dioxoprostanoate + NAD(P)+ -> (5Z)-(15S)-11-alpha-hydroxy-9,15-dioxoprosta-13-enoate + NAD(P)H + H+.