title: Structures of novel bufadienolides in the eggs of a toad, Bufo marinus.
abstract: In this paper, we report chemical structures of five compounds including four novel polyhydroxylated cardiac steroids in the eggs of a toad, Bufo marinus. These cardiac steroids were purified by high-performance liquid chromatography, and their structures were determined to be 11 alpha,19-dihydroxy-telocinobufagin (I), 11 alpha-hydroxytelocinobufagin (II), 11 alpha,19-dihydroxymarinobufagin (III), 11 alpha-hydroxymarinobufagin (IV) and 19-hydroxytelocinobufagin (V) on the basis of spectral data of nuclear magnetic resonance and mass spectroscopy. All the five compounds showed biological activity, as tested by inhibition of Na+,K(+)-ATPase activity and of [3H]ouabain binding to the receptor on Na+,K(+)-ATPase. This is the first finding of bufadienolides as cardiac steroids in animal eggs.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Akizawa
authors.forename: T
authors.initials: T
authors.lastname: Mukai
authors.forename: M
authors.initials: M
authors.lastname: Matsukawa
authors.forename: M
authors.initials: M
authors.lastname: Yoshioka
authors.forename: J F
authors.initials: JF
authors.lastname: Morris
authors.forename: V P
authors.initials: VP
authors.lastname: Butler
mesh_terms: D000818:Animals; D002018:Bufanolides / Q000032:analysis* / Q000494:pharmacology; D002024:Bufo marinus; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D010063:Ovum / Q000737:chemistry*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
chemical_list: D002018:Bufanolides; D000254:Sodium-Potassium-Exchanging ATPase