Isopentylated diphenyl ether derivatives from the fermentation products of an endophytic fungus Phomopsis fukushii

Three new isopentylated diphenyl ethers, ( 1 – 3 ), together with two known isopentylated diphenyl ethers derivatives ( 4 and 5 ) were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii . Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1 – 3 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1–3 showed strong activity with diameter of inhibition zone (IZD) of 21.8 ± 2.4 mm, 16.8 ± 2.2 mm, and 15.6 ± 2.0 mm, respectively.