5-[(2E,3aS,4R,5R,6aS)-5-hydroxy-4-[(1E,3S)-3-({5-[(2E,3aS,4R,5R,6aS)-5-hydroxy-4-[(1E,3S)-3-hydroxy-4-methyloct-1-en-6-ynyl]octahydrocyclopenta[1,2-a][5]annulen-2-ylidene]-1-oxopentyl}oxy)-4-methyloct-1-en-6-ynyl]octahydrocyclopenta[1,2-a][5]annulen-2-ylidene]pentanoic acid