THE TITLE MONOSUCCINATE DERIVATIVE OF MELAMPOMAGNOLIDE B [SYSTEMATIC NAME: 4-(((1aR,7aS,10aS,10bS,E)-1a-methyl-8-meth-yl-ene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-deca-hydro-oxireno[2',3':9,10]cyclo-deca-[1,2-b]furan-5-yl)meth-oxy)-4-oxo-butan-oic acid], C19H24O7, was obtained from the reaction of melampomagnolide B with succinic anhydride under nucleophilic addition reaction conditions. The mol-ecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings. The inter-nal double bond in the ten-membered ring has the cis geometry (i.e. it is the E isomer). The lactone ring has an envelope-type conformation, with the (chiral) C atom opposite the lactone O atoms as the flap atom. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into chains parallel to the b-axis direction.