A New Biphenyl from the Fermentation Broth of Plant Endophytic Fungus Pestalotiopsis zonata isolated from Cyrtotachys lakka

Abstract Aim To investigate the chemical constituents of the fermentation broth of the plant endophytic fungus Pestalotiopsis zonata isolated from Cyrtotachys lakka in Hainan, China. Method Compounds 1–4 were separated and purified by silica gel chromatography and Sephadex LH-20. Their structures were elucidated by extensive spectroscopic analysis. Compound 1 was tested for its antibacterial activity against the bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae , methicillin resistant Staphylococcus aureus, Acinetobacter baumannii and vancomycin-resistant Enterococcus faecium . Results Four compounds including one new compound named 2′-acetyl-4′, 4-dimethoxybiphenyl-2-carbaldehyde ( 1 ) were isolated from this fungus. Their IC 50 values are 0.75, 0.75, 0.82, 0.81, 0.84, 0.90 and 0.87 μm·mL −1 , respectively. Conclusion Compound 1 was a new biphenyl and it shows weak activity towards those bacteria. Compounds 2–4 were isolated from this fungus for the first time.