Antibacterial and cytotoxic xanthones from the roots of Cratoxylum formosum.

Chemical investigation of the roots of Cratoxylum formosum has resulted in the isolation and characterization of xanthones: three new, named formoxanthone A-C and three known together with three known anthraquinones. Their structures were established on the basis of analysis of spectroscopic evidence. In addition, antibacterial and cytotoxic activities of the isolates were also evaluated.