Two new polyketides from a marine sediment-derived fungus Eutypella scoparia FS26

Two new polyketides, 7,8-dihydroxy-3,5,7-trimethyl-8,8a-dihydro-1H-isochromen-6(7H)-one (1) and 6-(hydroxymethyl)-2,2-dimethyl-3,4-dihydro-2H-chromene-3,4-diol (2), together with a known nitrogen-containing polyketide (cytochalasin-type of metabolites), [12]-cytochalasin (3), have been isolated from the fermentation broth of a marine sediment-derived fungus Eutypella scoparia FS26 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. The absolute configurations of compound 1 were determined by NOESY analysis and the literature data were compared with circular dichroism (CD) spectroscopy. The cytotoxic effects on MCF-7, NCI-H460 and SF-268 cell lines of all compounds were evaluated by the sulforhodamine B method.