Prenylated Diphenyl Ethers from the Marine Algal-Derived Endophytic Fungus Aspergillus tennesseensis .

Considerable attention has been paid to marine derived endophytic fungi, owing to their capacity to produce novel secondary metabolites with potent bioactivities. In this study, two new compounds with a prenylated diphenyl ether structure-diorcinol L (1) and (R)-diorcinol B (2)-were isolated from the marine algal-derived endophytic fungus Aspergillus tennesseensis, along with seven known compounds: (S)-diorcinol B (3), 9-acetyldiorcinol B (4), diorcinol C (5), diorcinol D (6), diorcinol E (7), diorcinol J (8), and a dihydrobenzofuran derivative 9. Their structures were elucidated by extensive NMR spectroscopy studies. Compound 2 represents the first example of an R-configuration in the prenylated moiety. All these isolated compounds were examined for antimicrobial and cytotoxic activities. Compounds 1-9 exhibited antimicrobial activities against some human-and plant-pathogenic microbes with MIC values ranging from 2 to 64 mu g/mL. Moreover, compound 9 displayed considerable inhibitory activity against the THP-1 cell line in vitro, with an IC50 value of 7.0 mu g/mL.