Tersone A-G, New Pyridone Alkaloids from the Deep-Sea Fungus Phomopsis tersa .

Four phenylfuropyridone racemates, (±)-tersones A-C and E ( 1 - 3 , 5 ), one phenylpyridone racemate, (±)-tersone D ( 4 ), one new pyridine alkaloid, tersone F ( 6 ), single new phenylfuropyridone, tersone G ( 7 ) and two known analogs 8 and 9 were isolated from the deep-sea fungus Phomopsis tersa . Their structures and absolute configurations were characterized on the basis of comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) calculations. Moreover, compounds 1 - 9 were evaluated for in vitro antimicrobial and cytotoxic activity. Compounds 5b and 8b exhibited antibacterial activity against S. aureus with the MIC value of 31.5 μg/mL, while compound 5b showed cytoxic activities against SF-268, MCF-7, HepG-2 and A549 cell lines with IC ₅₀ values of 32.0, 29.5, 39.5 and 33.2 μM, respectively.