title: De-acetyl-cinobufalactam monohydrate.
abstract: 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.
authors.affiliation: Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drugs Research, Institute of Traditional Chinese Medicine and Natural Products, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Hong-Jin
authors.initials: HJ
authors.lastname: Tang
authors.affiliation: Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drugs Research, Institute of Traditional Chinese Medicine and Natural Products, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Yuan
authors.affiliation: Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drugs Research, Institute of Traditional Chinese Medicine and Natural Products, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Tian
authors.affiliation: Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drugs Research, Institute of Traditional Chinese Medicine and Natural Products, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Ruan
authors.affiliation: Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drugs Research, Institute of Traditional Chinese Medicine and Natural Products, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Ren-Wang
authors.initials: RW
authors.lastname: Jiang