In summary, a series of novel xanthone analogs based on
a-mangostin were synthesized and a-mangostin was efficiently
converted to b-mangostin and c-mangostin. Cytotoxicity activity
screening using 5 human cancer cell lines identified potent cytotoxic
agents such as 4a, 6a, 9, 13, 15, and 16 structure–activity
relationship studies revealed that phenol groups on C3 and C6
are critical to inhibition activity to cancer cell lines and C4 modification
is capable to improve activity and drug-like properties.
These findings provide important information on the structural
features that influence the biological activities within this class
of compounds, and offer new possibilities for further explorations
in analog design. Based on the SAR studies, further study for mode
of action of these prenylated xanthones is under progress.