Sesquiterpenes and other constituents of Xylaria sp. NC1214, a fungal endophyte of the moss Hypnum sp.

Abstract Oxygenated guaiane-type sesquiterpenes, xylaguaianols A−D ( 1 – 4 ), an iso-cadinane-type sesquiterpene isocadinanol A ( 5 ), and an α -pyrone 9-hydroxyxylarone ( 6 ), together with five known sesquiterpenes ( 7 – 11 ), and four known cytochalasins ( 12 – 15 ) were isolated from a culture broth of Xylaria sp. NC1214, a fungal endophyte of the moss Hypnum sp. The structures of all compounds were elucidated by the analysis of their spectroscopic data and relative configurations of 1 – 5 were determined with the help of NMR NOESY experiments. Cytochalasins C ( 12 ), D ( 13 ), and Q ( 14 ) were investigated for their cytotoxic activity against five tumor cell lines. Cytochalasin D showed significant cytotoxicity against all five cell lines, with IC 50 s ranging from 0.22 to 1.44 μM, whereas cytochalasins C and Q exhibited moderate, but selective cytotoxicity.