The chemical constituents of endophytic fungus of Gannan navel orange.

A new drimane sesquiterpene 11-methoxyl-danilol () was obtained from endophytic fungus of Gannan navel orange pulp. Its structure was established to possess a natural rarely-occurring tricyclic acetal fused ring system by means of spectroscopic data analyses. Meanwhile, five known compounds danilol (), redoxcitrinin (), euphorbol (), ergosta-7,24(24')-dien-3-ol (), and ergosta-4,6,8(14),22-tetraen-3-one () were also co-isolated in this fungus. The results of antibacterial and cytotoxic activity screenings showed that compound displayed antibacterial activities against and MRSA (methicillin-resistant ) with MIC value of 50 μg/mL. [Figure: see text].