2-[(8-Meth-oxy-carbonyl-4b,8-dimethyl-4b,5,6,7,8,8a,9,10-octa-hydro-phenan-thren-3-yl)amino]-3,5-dinitro-benzoic acid ethyl acetate monosolvate.

The title compound, C(25)H(27)N(3)O(8)·C(4)H(8)O(2), has a diterpene skeleton in which the fused cyclo-hexane rings exhibit chair and half-chair conformations. An intra-molecular C-H⋯O hydrogen bond occurs. In the crystal, N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds are observed.