RESUMEN
Objective Try to find the new biological compounds, the research on the chemical constituents in the fermentation products of an endophytic fungus Phomopsis fukushii had been carried out. Methods The chemical constituents in this fermentation products were isolated by silica gel, Sephadex LH-20 column chromatographies and RP-HPLC methods. Their structures were elucidated by using various spectroscopic techniques. Results Four pentylated diphenyl ethers (1-4) were isolated from this fermentation products, and the new compound (1) was evaluated for its anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. Compounds 2-4 were identified as diorcinol C, diorcinol D, and diorcinol E. Conclusion Compounds 2-4 are isolated from the fermentation products of endophytic fungus Phomopsis fukushii for the first time. Compound 1 is a new compound named phomodiphenyl ether A and given the system name of 1-[4-(3-hydroxy-5-methylphenoxy)-2-methoxy-6-methylphenyl]-3-methylbut- 3-en-2-one. Compound 1 also shows strong anti-MRSA activity with MIC90 value of (54 ± 4) μg/mL. This valve is close to that of positive control, levofloxacin with MIC90 value of [≥ (56 ± 6) μg/mL].