Abstract

• Three cytotoxic xanthones (1-3), together with other ten known compounds, have been isolated from the barks of Cratoxylum cochinchinense Blume. (Mei-thanyo), collected from Kachin State, Northern Myanmar. These structures were established on the basis of extensive spectroscopic methods. Among the isolated compounds, six xanthones and one anthraquinone were evaluated for their cytotoxicities by using the MTT assay. Compound 1 showed a significant cytotoxicity against all tested human cancer cell lines with IC50 values in the range 3-9 μM, on average lower than the anticancer drug cisplatin. Compounds 2 and 3 exhibited, instead, high cytotoxicity only against some cell lines. In striking contrast, other compounds showed from moderate to no activity.