The molecule is a prostaglandin carboxylic acid anion resulting from the removal of the proton from the carboxy group of prostaglandin A2. It is a conjugate base of a prostaglandin A2.
(Z)-7-[(1R,2S)-2-[(E,3S)-3-hydroxyoct-1-enyl]-5-oxocyclopent-3-en-1-yl]hept-5-enoate