Two new benzofurans from Gastrodia elata and their DNA topoisomerases I and II inhibitory activities

Abstract Two new benzofurans, 1-furan-2-yl-2-(4-hydroxyphenyl)-ethanone (1) and 5-(4-hydroxybenzyloxymethyl)-furan-2-carbaldehyde (2), together with five known compounds, 4-hydroxybenzyl methyl ether (3), 5-(hydroxymethyl)-furfural (4), gastrodin (5), β-sitosterol (6) and β-sitosterol glucoside (7) were isolated from the rhizome of GASTRODIA ELATA Blume. In DNA topoisomerase I and II inhibition assays IN VITRO at a concentration of 20 μM, 1 showed potent inhibitory activity, 66 % and 71 % inhibition, respectively, compared to the positive control compounds, camptothecin and etoposide, 71 % and 22 % inhibition, respectively. All of these compounds exhibited weak or no cytotoxicities against human colon carcinoma cell line (HT-29), human breast carcinoma cell line (MCF-7) and human hepatocellular carcinoma cell line (HepG-2).