The molecule is a derivative of succinic acid in which one of the carboxy groups is esterified by the C-21 hydroxy group of cortisol (hydrocortisone). It is a dicarboxylic acid monoester, a hemisuccinate and a tertiary alpha-hydroxy ketone. It derives from a cortisol.
4-[2-[(8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-10,13-dimethyl-3-oxo-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-17-yl]-2-oxoethoxy]-4-oxobutanoic acid