Antifungal Pseuboyenes A-J, Bergamotene-Derived Sesquiterpenoids from a Cold-Seep-Derived Pseudallescheria boydii .

A chemical investigation of a cold-seep-sediment-derived fungus, Pseudallescheria boydii CS-793, resulted in characterization of 10 novel bergamotene-derived sesquiterpenoids, pseuboyenes A-J ( 1 - 10 ). Their structures were elucidated by spectroscopic and X-ray crystallographic analyses as well as using the modified Mosher's method. Compound 1 represents the first example of a β -bergamotene containing a 6-oxobicyclo[3.2.1]octane nucleus adducted with a methyl lactate unit, while 8 - 10 involve a skeletal rearrangement from bergamotene. Compounds 2 - 5 showed significant antifungal activities against Colletotrichum gloeosporioides Penz. and Fusarium oxysporum with MICs ranging from 0.5 to 8 μ g/mL. Compound 4 exhibited an in vitro anti- F. proliferatum effect with an EC 50 value of 1.0 μ g/mL.