The title compound, C(26)H(23)N(5)O(8), was prepared and its structure investigated to further develop a working hypothesis for the essential binding pharmacophore for ligands of the System Xc- transporter [Patel et al. (2004 ▶). Neuropharmacology, 46, 273-284]. The hydrazone group displays an E geometry and the isoxazole double bond and C=N group of the hydrazone are in an s-cis relationship. The secondary amino NH group forms an intra-molecular N-H⋯O hydrogen bond to a ring nitro group. There is a dihedral angle of 44.27 (5)° between the isoxazole plane and the hydrazone group plane.