Secondary metabolites from Basotho medicinal plants. II. Bulbine capitata

The medicinal plant Bulbine capitatais used by the Basotho of southern Africa as a mild purgative and to cure gonorrhea infections. Organic extracts of the powdered root were found to be rich in anthraquinones, which may be responsible for the reported laxative effects. Examination of B. capitata led to the isolation of five known anthraquinones: chrysophanol, knipholone, isoknipholone, 10,7´-bichrysophanol and chrysalodin, and one new anthraquinone glycoside, M-4´-demethylknipholone-2´-O-l-D-glucopyranoside.