PRENYLATED XANTHONES FROM GARCINIA-LIVINGSTONEI

Five prenylated xanthones have been isolated from the root bark of Garcinia livingstonei of which four are novel natural products. The xanthone, 12b-hydroxy-des-D-garcigerrin A was previously isolated from G. gerrardii. Structure elucidation was achieved by a combination of one- and two-dimensional NMR spectroscopic techniques, mass spectroscopy and chemical methods. Two compounds are fungicidal against Cladosporium cucumerinum, a plant pathogenic fungus, whereas a third shows growth inhibitory activity against human colon carcinoma cell lines.