Caryophyllene sesquiterpenes from a chaetomium globosum endophyte of the Canadian medicinal plant empetrum nigrum

Punctaporonins T (1) and U (2), new caryophyllene sesquiterpenes, were isolated with three known punctaporonins, A (3), B (4), and C (5), from the endophytic fungus Chaetomium globosum (TC2-041). The structures and relative configurations of punctaporonins T and U were elucidated based on a combination of HRESIMS, 1D/2D NMR spectroscopic analysis, and X-ray diffraction analysis, while their absolute configuration is presumed to be consistent with the co-isolated 3–5 on biogenetic arguments. Compound 1 showed weak inhibitory activity against both Mycobacterium tuberculosis and Staphylococcus aureus.