Harzianumnones A and B: two hydroxyanthraquinones from the coral-derived fungus Trichoderma harzianum†
Two new hydroxyanthraquinones, harzianumnones A (1) and B (2), together with seven known analogs (3–9), were isolated from the soft coral-derived fungus Trichoderma harzianum (XS-20090075). Their chemical structures were elucidated by extensive spectroscopic investigation. The absolute configurations of 1 and 2 were determined by ECD calculation and single-crystal X-ray diffraction. Compounds 1 and 2 were identified as a pair of epimers, which are the first example of hydroanthraquinones from T. harzianum. Compounds 7 and 8 exhibited cytotoxicity against hepatoma cell line HepG2 with IC50 values of 2.10 and 9.39 μM, respectively. Compound 7 was still found to show cytotoxicity against cervical cancer cell line HeLa with an IC50 value of 8.59 μM.