Two new xanthons from Garcinia rigida leaves
Two new xanthons, musaxanthone (1) and asmaxanthone (2) were isolated from the leaves of Garcinia rigida. The structures were determined by means of spectroscopic analysis.
Prenylated xanthones fromGarcinia livingstonei
Abstract 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.
X-Ray crystal structure of sarothralin, a novel antibiotic compound from Hypericum japonicum
A novel antibiotic compound, sarothralin, from Hypericum japonicum Thunb. (Sarothra japonica Thunb.) has been isolated and its stereostructure elucidated using spectroscopin and X-ray Crystallographic techniques.