Spirobisnaphthalenes from the Mangrove-Derived Fungus Rhytidhysteron sp AS21B

Three new spirobisnaphthalenes (1-3) were isolated from the mangrove-derived fungus Rhytidhysteron sp., together with five known derivatives (4-8). The structures of the compounds were established on the basis of extensive spectroscopic data, and the relative configurations of their stereogenic carbons were determined by a single-crystal X-ray crystallographic analysis. Compounds 3-5 displayed cytotoxicity against both cancer cell lines, MCF-7 and CaSki, while 2 was active only on CaSKi cells.