Cytotoxicity of natural compounds isolated from the seeds of Garcinia afzelii.

The new compounds guttiferone O ( 1) and 3-methoxycheffouxanthone ( 2) have been isolated from the seeds of Garcinia afzelii Engl., together with nine known compounds: 2-hydroxy-1,7-dimethoxyxanthone ( 3), smeathxanthone A ( 4), 1,5-dihydroxyxanthone ( 5), 1,6-dihydroxy-5-methoxyxanthone ( 6), cheffouxanthone ( 7), 1,3,5-trihydroxyxanthone ( 8), smeathxanthone B ( 9), isoxanthochymol ( 10) and guttiferone E ( 11). Their structures were elucidated by means of 1D and 2D-NMR techniques. All the isolates showed high cytotoxic activity and were found inactive when tested against HIV and influenza viruses.