Die toxischen und sedierend wirkenden Bufadienolide von <i>Kalanchoe</i><i>daigremontiana</i> H<scp>AMET</scp><i>et</i> P<scp>ERR</scp>

The Toxic and Sedative Bufadienolides of Kalanchoe daigremontiana H AMET et P ERR . From the toxic Crassulacee Kalanchoe daigremontiana five biosynthetically related bufadienolides have been isolated and structurally elucidated by X‐ray and 1 H‐ and 13 C‐NMR spectroscopy. The compounds were identified as bersaldegenin 1,3,5‐orthoacetate ( 2 ), bersaldegenin 1‐acetate ( 4 ), bersaldegenin 3‐acetate ( 3 ), 1β,3β,5,11α,14‐pentahydroxy‐12,19‐dioxo‐5β,14β‐bufa‐20,22‐dienolide 1,3,5‐orthoacetate ( = daigremontianin; 1 ), and 3β‐acetoxy‐1β,5,14‐trihydroxy‐5β,14β‐bufa‐20,22‐dienolide ( = daigredorigenin‐3‐acetate, 5 ). According to the pharmacological investigations, the two orthoacetates 1 and 2 comprise the positive inotropic, sedative, and toxic activity of the plant.