New Chemical Constituents from the Endophytic Fungus Xylariapapulis Cultivated on Taiwanese Lepidagathisstenophylla

The endophytic strain Xylaria papulis was originated from the stem of Taiwanese Lepidagathis stenophylla C. B. Clarke ex Hayata (Acanthaceae) growing in the Hengchun Peninsula of southern Taiwan. Bioassay-guided fractionation of an EtOAc -soluble fraction of the liquid fermentate of this strain resulted in the isolation of two new isopimarane-type diterpene glycosides compounds, i.e., xylapapusides A & B (1 & 2), along with five previously identified compounds, 3–7. The structures of 1 and 2 were elucidated by detailed spectroscopic analysis including 1H- and 13C-NMR, COSY, HSQC, HMBC, and HR-ESI-MS, while the structures of the known compounds 3–7 were deduced from comparison of their spectral data with those in the literature. The effects of some isolates on the inhibition of NO production in lipopolysaccharide-activated RAW 264.7 murine macrophages were evaluated. Xylapapuside A (1) showed most potent of NO inhibition with E maxvalue of 34.3 μM.