Lactones from the Sponge-Derived Fungus Talaromyces rugulosus.

The marine-derived fungus isolated from the Mediterranean sponge and cultured on solid rice medium yielded seventeen lactone derivatives including five butenolides (-), seven (3)-resorcylide derivatives (-), two butenolide-resorcylide dimers ( and ), and three dihydroisocoumarins (-). Among them, fourteen compounds (-, -) are new natural products. The structures of the isolated compounds were elucidated by 1D and 2D NMR (Nuclear Magnetic Resonance) spectroscopy as well as by ESI-HRMS (ElectroSpray Ionization-High Resolution Mass Spectrometry). TDDFT-ECD (Time-Dependent Density Functional Theory-Electronic Circular Dichroism) calculations were performed to determine the absolute configurations of chiral compounds. The butenolide-resorcylide dimers talarodilactones A and B ( and ) exhibited potent cytotoxicity against the L5178Y murine lymphoma cell line with IC values of 3.9 and 1.3 µM, respectively.