5,11-Epoxymegastigmanes from the leaves of Asclepias fruticosa).

Five new megastigmane glucosides and one of their aglycones were isolated, along with (6S,9R)-roseoside, from the polar fraction of the leaves of Asclepias fruticosa, and the structures were determined by spectroscopic methods. Most of them have an epoxy-linkage between C-5 and C-11. The configurations at C-3 and C-9 for each compound were confirmed to be S and R, respectively, by application of the modified Mosher's method.