Xanthone derivatives from Aspergillus sydowii, an endophytic fungus from the liverwort Scapania ciliata S. Lac and their immunosuppressive activities

Three new compounds, sydoxanthone A (1), sydoxanthone B (2), and 13-O-acetylsydowinin B (3) together with seven known biosynthetically related compounds (4-10), were isolated from an endophytic fungus Aspergillus sydowii, occurring in the liverwort Scapania ciliata S. Lac. Their suppressive effect on the Con A-induced and LPS-induced proliferations of mouse splenic lymphocytes was evaluated in vitro.