Acridone alkaloids from the root bark of Severinia buxifolia in Hainan

Eight new acridone alkaloids, buxifoliadines-A-H together with nine known a cridone compounds, were isolated and characterized from the root bark of Se verinia buxifolia which was collected in Hainan province, China. Their stru ctures were determined by spectroscopic methods. The relationship between a cridone alkaloids with collecting area is discussed. The C-13-NMR spectra o f the prenyl substituents at C-2 and/or C-4 of N-unsubstituted acridone alk aloids are also discussed.