Antimicrobial Sesquiterpenoid Derivatives and Monoterpenoids from the Deep-Sea Sediment-Derived Fungus SD-330.

Two new antimicrobial bisabolane-type sesquiterpenoid derivatives, -aspergoterpenin C (compound ) and 7--methylhydroxysydonic acid (), and two new butyrolactone-type monoterpenoids, pestalotiolactones C () and D (), along with a known monoterpenoid pestalotiolactone A () and four known bisabolane sesquiterpenoids (-), were isolated and identified from the deep-sea sediment-derived fungus SD-330. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and the absolute configurations of the new compounds - were determined by the combination of NOESY and TDDFT-ECD calculations and X-ray crystallographic analysis. Additionally, we first determined and reported the absolute configuration of the known monoterpenoid pestalotiolactone A () through the X-ray crystallographic experiment. All of these isolated compounds were evaluated for antimicrobial activities against human and aquatic pathogenic bacteria. Compounds , , and exhibited selective inhibitory activities against zoonotic pathogenic bacteria such as , , and , with MIC values ranging from 1.0 to 8.0 μg/mL.