Anti-bacterial chromones from cultures of the endophytic fungus Bipolaris eleusines.

One previously undescribed chromone (S)-5-hydroxyl-2-(1-hydroxyethyl)-7-methylchromone (1) and one known analogue (2), as well as four known sativene-type sesquiterpenoids bipolenins A‒C (3‒5), were isolated from cultures of the endophytic fungus Bipolaris eleusines. Their structure were elucidated by extensive spectroscopic methods and the data comparison with those reported in the literature. Compounds 1 and 2 showed weak inhibitory activities against Staphylococcus aureus subsp. aureus with the inhibition rates of 56.3 ± 0.48 and 32 ± 1.27%, respectively, at the concentration of 128 μg/mL.