Xanthones from a lignicolous freshwater fungus (BCC 28210)

Four xanthones (1‒4) and a known compound, mansonone D (5), were isolated from the lignicolous freshwater fungus BCC 28210 (family, Chaetosphaeriaceae). The structures of these compounds were elucidated by extensive spectroscopic analysis. Among the isolated metabolites, compound 2 and the known mansonone D (5) displayed antimalarial activity against Plasmodium falciparum K1 with IC50 values of 7.75 and 0.55 μg/mL, respectively. Compound 4 displayed antibacterial activity against Bacillus cereus with an MIC value of 6.25 μg/mL.