Xanthone derivatives from the fermentation products of an endophytic fungus Phomopsis sp.

Abstract Three new xanthones, 1,5-dihydroxy-3-hydroxyethyl-6-methoxycarbonylxanthone ( 1 ), 1-hydroxy-5- methoxy-3-hydroxyethyl-6-methoxycarbonylxanthone ( 2 ), and 1-hydroxy-3-hydroxyethyl- 8-ethoxycarbonylxanthone ( 3 ), along with seven known xanthones ( 4 – 10 ) were isolated from the fermentation products of an endophytic fungus Phomopsis sp.. Their structures were elucidated by spectroscopic methods including extensive 1D- and 2D-NMR techniques. Compounds 1 – 10 were also tested for their cytotoxicity against five human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) by MTT method using paclitaxel as positive control. Compounds 1 and 3 showed cytotoxicity against A549 cell lines with IC50 values of 3.6 and 2.5 μM, respectively. In addition, 1 was cytotoxic to MCF7 cells with IC50 value of 2.7 μM.