Die Glykoside von Vincetoxicum hirundinaria M EDIKUS . 1. Mitteilung: Isolierungen und Spaltprodukte. Glykoside und Aglykone, 316. Mitteilung

The dried roots of Vincetoxicum hirundinaria M EDIKUS , collected in the lake of Garda area, yielded ca. 6% of a crude glycoside mixture, of which 5,16% consisted of relatively weakly polar material. After mild acid hydrolysis of the latter, 7 sugars could be identified through paper and thin layer chromatography, and paper electrophoresis. Of these D ‐cymarose, L ‐diginose, D ‐digitoxose, and a small amount of lilacinobiose could be isolated in crystalline form. Of the other three sugars, D ‐oleandrose was characterised as a crystalline derivative, whereas boivinose and canarose could only be identified through paper and thin layer chromatography, and paper electrophoresis. Four crystalline genins (B, D, E, G) and a glycoside (F) were isolated from the genin extract. Of these, D was very unstable and therefore thus was not further investigated. B, E, and F were shown to be 15‐oxasteroids, a type of steroids so far not found in nature. Very probably, G also represents a 15‐oxasteroid. The four substances B, E, G, and F were given the following trivial names: B = anhydrohirundigenin, E = hirundigenin, G = vincetogenin, and F = hirundoside‐A. F is an oleandroside of anhydrohirundigenin. The structures of hirundigenin and anhydrohirundigenin have already been elucidated [35].