Cytotoxic diaporindene and tenellone derivatives from the fungus Phomopsis lithocarpus

Nine new compounds, including five natural rarely-occurring 2,3-dihydro-1H-indene derivatives named diaporindenes E-I ( 1 - 5 ), and four new benzophenone analogues named tenellones J-M ( 6 - 9 ) were isolated from the deep-sea sediment-derived fungus Phomopsis lithocarpus FS508. All of the structures for these new compounds were fully characterized and established on the basis of interpretation of spectroscopic data, NMR spectra, and ECD calculation and single-crystal X-ray diffraction experiment. The potential antitumor activities of compounds 1 - 9 were evaluated subsequently by SRB methods against four tumor cell lines SF-268, MCF-7, HepG-2, and A549. Among them, compound 7 exhibited cytotoxic activity against SF-268 cell line with the IC50 value of 11.36 μM.