The title compound is a semisynthetic derivative of triptolide (I), a substance isolated from the root xylem of the Chinese medicinal plant Tripterygium wilfordii. Condensation of (I) with succinic anhydride (II) in hot pyridine furnished the corresponding hemisuccinate ester. This was converted to the corresponding sodium salt by treatment with aqueous NaHCO3 and then isolated by lyophilization of the filtered solution.