The aims of this study was to isolate compounds from the leaves of methanol extract of Garcinia cowa and to evaluated their cytotoxic activity against breast (MCF-7) and lung (H-460) cell lines. The dichloromethane fraction was separated by successive silica gel column chromatography to give three compounds. Based on spectroscopic comparison with those of the literature these compounds were elucidated as methyl 2,4,6-trihydroxy-3-(3-methylbut-2-enyl)benzoate (1), garcinisidone-A (2) and methyl 4,6dihydroxy-2-(4-methoxy-5-(3-methylbut-2-enyl)-3,6-dioxocylohexa-1,4-dienyloxy)-3-(3-methylbut-2-enyl)benzoate (3). Compound 1, 2 and 3 had IC50 value of 21.0 ± 10.2 µM, 21.2 ±8.4 µM and 17.2 ± 6.2µM against MCF-7, while only compound (2) was found to be in active against H-460 with IC50 value of 18.1 ± 6.7 µM. Conclusion: The results indicate that G. cowa leaves could be important sources of natural cytotoxic compounds and only compound (2) had activity against H-460 cell lines.
Key words: Structure elucidation, NMR spectroscopy, xanthone, benzoate, Garcinia cowa Roxb., cytotoxic activity, MCF-7, H-460