Cardenolides from Nierembergia aristata.

The EtOAc extract of the whole plant of the Argentinian species Nierembergia aristata showed significant cytotoxicity against eleven different cancer cell lines. In addition to several known compounds, bioassay-guided fractionation led to the isolation of three new cardenolides, 17-epi-11 alpha-hydroxy-6, 7-dehydrostrophanthidin-3-O-beta-boivinopyranoside[1],6, 7-dehydrostrophanthidin-3-O-beta-boivinopyranoside [2], and 6,7-dehydrostrophanthidin-3-O-beta-oleandropyranoside[3], of which the latter demonstrated activity against all the cell lines tested. To our knowledge, this is the first report of the isolation of cardiac glycosides from a species in the Solanaceae.