Cytotoxic and antibacterial xanthones from the roots of <i>Maclura cochinchinensis</i>

Abstract

Three new furanoxanthones, macochinxanthones A-C (<b>1</b>-<b>3</b>) and sixteen known xanthones (<b>4</b>-<b>19</b>) were isolated from the roots of <i>Maclura cochinchinensis.</i> Their structures were elucidated by spectroscopic analysis including NMR, UV and IR, as well as mass spectrometry. Chiral-phase HPLC analysis of <b>1</b>-<b>3</b> revealed that they were scalemic mixtures with an enantiomeric excess (ee) of 0.05%, 36.8% and 8%, respectively. Most of the isolated xanthones exhibited potent cytotoxicity against four cancer cell lines (KB, HelaS3, A549 and HepG2) with IC₅₀ values in the range of 1.29-90.15 <i>µ</i>M. In addition, many of them displayed antibacterial activity against Gram-positive bacteria and Methicillin resistant <i>Stephylococus aureus</i> (MRSA) with MIC values in the range of 4-128 <i>µ</i>g/mL.