The cardenolides of Speirantha convallarioides.

The cardenolide pattern of Speirantha convallarioides has been investigated and compared with Convallaria majalis, a close relative with active cardenolides and used extensively as a cardiac remedy. Five cardenolides were isolated from small amounts (25 g) of plant material by application of an efficient isolation procedure. Their identification was achieved by an easy concept mainly based on detailed analysis of 1H-NMR and DCI-NH3-mass spectral data. Rhodexin A(1) and lokundjoside (2) are the major cardenolides (42% and 31% of the total cardenolides in the plant), while digitoxigenin-glucoside (3), periplorhamnoside (4), and periplogenin-glucoside (5) are minor constituents of the cardenolide complex (3 to 4% each). Similarities in cardenolide patterns (structures of the aglycones, variability of the sugar portion) along with morphological and biogenetical characteristics support the classification of S. convallarioides as belonging in the same tribe Convallarieae as C. majalis within the family Convallariaceae.