Oleasides; novel cardenolides with an unusual framework in Nerium (Nerium 10).

During the course of re-investigation of the cardiac glycosides of Nerium, new cardenolides with a novel aglycone moiety were isolated and named oleasides A-F. The structure of the aglycone, oleagenin, was established as 3β-hydroxy-15 (14→8) abeo-5β-(8R)-14-oxo-card-20 (22)-enolide, and the sugar moieties were identified as D-diginose (oleaside A), D-digitalose (-B), β-D-glucosyl-D-diginose (-C), 4-O-β-D-glucosyl-D-digitalose (-D), β-gentiobiosyl-D-diginose (-E) and 4-O-β-gentiobiosyl-D-digitalose (-F).