Herzwirksame Glykoside aus der weissen Meerzwiebel. Konstitution des Scilliphäosids und des Glucoscilliphäosids. 55. Mitteilung über Herzglykoside [1]

Scilliphaeoside (I), C₃₀H₄₂O₉, and glucoscilliphaeoside (III), C₃₆H₅₂O₁₄, represent two minor glycosides which occur in the bulbs of the white sea onion or squill [Scilla (= Urginea) maritima (Baker) L.]. Glucoscilliphaeoside is easily converted into scilliphaeoside and D-glucose by selective enzymatic cleavage with β-glucosidases (e. g. strophanthobiase). Acid hydrolysis splits glucoscilliphaeoside into anhydroscilliphaeosidin (IV) and L-scillabiose (= β-D -glucosyl-L -rhamnose), scilliphaeoside yields the same anhydro-aglycone IV and L-rhamnose. The true genin scilliphaeosidin (VI), C₂₄H₃₂O₅, has now been gained by a combined oxidative and hydrolytic cleavage of the rhamnose residue of scilliphaeoside. By chemical evidence and spectroscopical data scilliphaeosidin is characterized as a trihydroxy-Δ⁴-steroid of the bufadienolide type. The assumed locations of the three hydroxylic functions at C-3, C-12 and C-14 are established by permanganate degradation of the lactone ring of di-O-acetyl-scilliphaeosidin (VII) to the etianic acid derivatives XIII and XIV, which are also available from digoxigenin. These correlations prove the structure of scilliphaeoside (I) as 12β-hydroxy-proscillaridin A, glucoscilliphaeos de (III) representing 12β-hydroxy-scillaren A.