Abstract

A new triprenylated xanthone, costatin (1), together with five known xanthones (2-6), was isolated from a branch of Garcinia costata (Guttiferae). The structure was elucidated on the basis of spectroscopic data. All xanthone derivatives were evaluated for antimalarial, anti-tuberculosis (TB), cytotoxicity against human breast adenocarcinoma cell line (MCF-7), anti-human KB-cell line and cytotoxicity against African green monkey kidney (Vero) cells. Costatin (1) exhibited significant antimalarial activity (IC<inf>50</inf> 1.57 μg/mL); however, it also showed comparable cytotoxic activity (IC <inf>50</inf> 1.12 μg/mL). © The Japan Institute of Heterocyclic Chemistry.