1-Hydroxy-10-methoxy-dibenz[ b, e]oxepin-6,11-dione ( 1) was obtained from the culture broth of a marine-derived fungus, Beauveria bassiana TPU942, isolated from a marine sponge collected at Iriomote Island in Okinawa, together with two known compounds, chrysazin ( 2) and globosuxanthone A ( 3). The structure of 1 was elucidated on the basis of its spectroscopic data (HREIMS, 1D and 2D NMR experiments including 1H– 1H COSY, HMQC and HMBC spectra). Dibenz[ b, e]oxepines are rare in nature, and only six natural products have been reported. Therefore, compound 1 is the seventh natural product in this class. Compounds 2 and 3 showed an antifungal activity against Candida albicans, and 3 inhibited the cell growth against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma). Compound 1 did not show an apparent activity in the same bioassays.
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