Die Pregnanderivate der Wurzeln von <i>Asclepias lilicina</i> W<scp>EIMARCK</scp>. II. Strukturbestimmungen Glyoside und Aglykone, 291. Mitteilung

Abstract

Abstract Partial formulae have been derived for the nine lilacinosides which were isolated, partly in pure form, and for two related substances which were only obtained as a mixture. These substances are derived basically from two pregnane derivatives (sarcostin and deacetyl‐metaplexigenin) present in partially benzoylated form. Of these were isolated genin B = 12,20‐di‐O‐benzoyl‐sarcostin ( 1 ), genin C = 12‐O‐benzoyl‐20‐O‐acetylsarcostin ( 2 ), and genin D, which could be identified with 12‐mono‐O‐benzoyl‐desacetyl‐metaplexigenin ( 4 ). These three genins are bound to different sugars, the latter being present as mono‐, di‐, tri‐ and probably tetra‐saccharides. The structures of these were partially derived: after mild hydrolysis three new disaccharides were obtained, which are named asclepobiose (U1), lilacinobiose (U2) and digalilobiose (U5). U1 and U2 were isolated in crystalline form. On hydrolysis U1 yielded 3‐O‐methyl‐6‐deoxy‐D‐allose (U3), U2 yielded 3‐O‐methyl‐6‐deoxyglucose (thevetose), and digitalose was obtained from U5.