Xylaria species are prolific natural product producers. Here, we report the characterization of a new glycosylated incisterol derivative, called xyloneside A ( 1 ) and two known lignans ( 2 and 3 ) from the ascomycetous Xylaria sp. FB. The structure of xyloneside A ( 1 ) was determined by 1D and 2D nuclear magnetic resonance spectra, high-resolution electrospray ionization mass spectrometry and electronic circular dichroism measurements. Xyloneside A ( 1 ) is composed of a 1,2,3,4,5,10,19-heptanorergosterane skeleton and a β- D-mannopyranose moiety. This is the first report of an incisterol derivative from an Ascomycete. The biological effects of the isolated metabolites on cytotoxicity, autophagy, cell-migration, and angiogenesis were evaluated.