Die Cardenolide von Parquetina nigrescens (A FZEL .) B ULLOCK . Glykoside und Aglykone, 270. Mitteilung [1]

Six crystalline (A, C, E, H, J and K) and six amorphous (α, γ, A 1 , D, D′, and G) but paperchromatographically homogenous cardenolides were isolated from the wood of Parquetina nigrescens (A FZEL .) B ULLOCK (= Periploca nigrescens A FZEL .) after fermentation with glucosidases. The presence of twelve more cardenolides was observed in paperchromatograms. Three of the mentioned compounds could be identified with known substances: A = strophanthidin (already isolated by S CHENKER et al. [3] from similar material), H = strophadogenin = 16β‐hydroxystrophanthidin and J = convallatoxin. A 1 , C, D, E, and K are new compounds whose structures will be reported in the following publication. The structures of α, γ, D′ and G are as yet unknown.