Secondary metabolites from Basotho medicinal plants. I. Bulbine narcissifolia

The medicinal plant Bulbine narcissifolia is used by the Basotho, Griqua, and whites of southern Africa for wound healing and as a mild purgative. Extraction of the powdered root has yielded acetosyringone, chrysophanol, knipholone, isoknipholone, 10,7'-bichrysophanol, and chrysalodin in addition to two new anthraquinone glycosides, knipholone-8-O-β-D-gentiobioside (1) and chrysalodin-10-β-D-gentiobioside (2). NMR spectroscopy was used to elucidate the structures of 1 and 2 and to show that 1 binds weakly to DNA.