Graphostromols A-K, Eleven New Chained Polyketides from the Deep-Sea-Derived Graphostroma sp.

Chromatographic separation of the AcOEt extract of the fermented cultures of the deep-sea-derived fungus Graphostroma sp. resulted in the isolation of 11 new chained polyketides, namely graphostromols A-K (1-11). The structures of the new compounds were established by the extensive analyses of their NMR and HR-ESI-MS data. The absolute configuration at C-11 in 1 was determined on the basis of the modified Mosher's method. Compounds 1-5, bearing a 2,2,10,10-tetramethyldodecane skeleton, were discovered for the first time from nature. All isolates were evaluated for their cytotoxicities against five different cancer cell lines (HeLa, Eca-109, Biu-87, Bel-7402, and PANC-1). However, none showed positive effects.