Die Glykoside der Blätter von Isoplexis isabelliana (WEBB) MASF.. 3. Mitteilung

The isolation, characterisation and chemical investigation of the cardiac glycosides of the dried leaves of Isoplexis isabelliana (WEBB) MASF. are described. 7 glucosides B, D, E, J (monoside), K, M, and 1 (monoside) could be obtained in homogenous form, 3 others were mixtures (“A” = A1 + A2, “C” = C1 + C2, and “G” = G + K). The substances B (gluco‐evatromonoside), D (cheiroside A), E (digitoxigenin‐glucosido‐6‐deoxyglucoside), J (digitoxigenin glucoside), and M (digitalinum verum) could be identified with known substances. The new glycosides are derived from 3 genins: digitoxigenin, uzarigenin, and xysmalogenin, which are directly bound to one of the following sugars: 6‐deoxyglucose, 2‐O‐acetyl‐6‐deoxy‐D‐glucose, 2,6‐dideoxy‐D‐arabinohexose (= D‐canarose), and 2,6‐dideoxy‐D‐ribohexose (= D‐digitoxose), terminated by a glucose unit. –Canarobiose, a new crystalline disaccharide of D‐glucose and D‐canarose, has also been obtained. –Apart from these cardiac glycosides 3 C21‐steroids have been isolated (in addition to the 2 known genins γ‐digiprogenin and purpnigenin), and their structures elucidated. The presence of 2 sapogenins has been detected.