Cytotoxic prenylated xanthones from Calophyllum inophyllum

Abstract

A new prenylated xanthone (1), named caloxanthone N, together with two known constituents, gerontoxanthone C (2) and 2-hydroxyxanthone (3), was isolated from the ethanolic extract of the twigs of Calophyllum inophyllum. Their structures were completely elucidated using a combination of 1D, 2D NMR techniques (COSY, HMQC, HMBC, and ROESY) and HR-ESI-MS analyses. Compounds 1 and 2 exhibited cytotoxicity against chronic myelogenous leukemia cell line (K562) with IC₅₀ values of 7.2 and 6.3 μg ml^− 1, respectively.

Keywords:

• Calophyllum inophyllum
• cytotoxic activity
• prenylated xanthone
• caloxanthone N

Acknowledgements

This research was financially supported by National Basic Research Program of China (2007CB116306) and the Science and Technology Foundation of Chinese Academy of Agricultural Sciences (RKY0421).