at C-1 in the xanthone nucleus (as in the 3 xanthones in the current
study), but reduced with the increase in the number of hydroxyl
groups in the C5 side chain (as in 8-deoxygartanin) (Suksamrarn
et al., 2006). The current results were partially consistent with this
correlation. a-Mangostin showed the most potent effects against
SK-MEL-28 since it possessed the highest activity among three
xanthones tested to induce both caspase 3 activity and loss of
DWm. However, 8-deoxygartanin treatment displayed similar toxicity
as c-mangostin. This indicates that the anti-cancer potency of
xanthones can be affected by their structures and also the type of
cell line screened.