The molecule is a steroid acid anion that is the conjugate base of fusidic acid, obtained by deprotonation of the carboxy group; major species at pH 7.3. It is a conjugate base of a fusidic acid.
(2Z)-2-[(3R,4S,5S,8S,9S,10S,11R,13R,14S,16S)-16-acetyloxy-3,11-dihydroxy-4,8,10,14-tetramethyl-2,3,4,5,6,7,9,11,12,13,15,16-dodecahydro-1H-cyclopenta[a]phenanthren-17-ylidene]-6-methylhept-5-enoate