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

Scilliphaeoside (I), C 30 H 42 O 9 , and glucoscilliphaeoside (III), C 36 H 52 O 14 , 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), C 24 H 32 O 5 , 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‐Δ 4 ‐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.