A new cyclic pentapeptide, pentaminolarin (1), and a new cytochalasin, xylochalasin (2), along with thirteen known compounds (3-15) were isolated from the wood-decaying fungus Xylaria sp. SWUF08-37. The absolute configurations of 1 were determined by a combination of Marfey's method and TDDFT ECD calculation and the absolute configurations of 2 were established by TDDFT ECD calculation. Compound 12 showed moderate cytotoxicity against HeLa (IC50 = 19.60 µg/mL), HT29 (IC50 = 17.31 µg/mL), HCT116 (IC50 = 14.28 µg/mL), MCF-7 (IC50 = 15.38 µg/mL), and Vero (IC50 = 24.97 µg/mL) cell lines by MTT assay. Compounds 1 and 2 showed slight cytotoxicity against all tested cancer cell lines.
Keywords: Xylariaceae; cyclic pentapeptide; cytochalasin; cytotoxic activity; wood decaying fungus.