De-acetyl-cinobufalactam monohydrate.

The title compound, C24H33NO4·H2O, the reaction product of de-acetyl-cinobufagin with ammonium acetate, consists of three cyclo-hexane rings (A, B and C), one five-membered ring (D), one six-membered lactone ring (E) and an epoxide ring (F). The stereochemistry of the ring junctures are A/B cis, B/C trans, C/D cis and D/F cis. Cyclo-hexane rings A, B and C have normal chair conformations. The five-membered ring D adopts an envelope conformation (with the C atom bearing the lactone ring as the flap) and the lactone ring E is planar. In the crystal, hy-droxy and water O-H⋯O and amine N-H⋯O hydrogen bonds involving carbonyl, hy-droxy and water O-atom acceptors link the mol-ecules into a three-dimensional network.