Prenylhydroquinone-derived metabolites from cultures of basidiomycete Panus similis

Two undescribed prenylhydroquinone-derived metabolites, panusidones A (1) and B (2), were isolated from cultures of basidiomycete Panus similis TBRC-BCC 52578, together with the structurally related known compounds panepoxydone (3) and panepoxydione (4). The structure was elucidated by extensive NMR spectroscopic analyses and mass spectrometry data. Panusidone A (1) showed weak antitubercular activity against Mycobacterium tuberculosis H37Ra (MIC 50 µg/ml). It was devoid of cytotoxicity to NCI-187 and MCF-7 human tumor cell-lines, while the known major co-metabolites, panepoxydone and panepoxydione, showed significant proliferation inhibitions.