Stachybotrysins A-G, Phenylspirodrimane Derivatives from the Fungus Stachybotrys chartarum

Seven new phenylspirodrimane derivatives named stachybotrysins A-G (2-8), together with five known compounds (1, 9-12), were isolated from Stachybotrys chartarum CGMCC 3.5365. Stachybotrysin D (5) is the first reported example of a naturally occurring alcoholic O-sulfation of a phenylspirodrimane, and stachybotrysins F and G (7 and 8) are the first examples possessing an isobenzotetrahydrofuran ring with an acetonyl moiety attached. The structures of these compounds were elucidated on the basis of extensive spectroscopic data analysis and by comparison with reported data. The absolute configurations of 1-8 were determined by X-ray single-crystal diffraction, electronic circular dichroism (ECD), and calculated ECD. Compounds 1 and 8 displayed anti-HIV activity with IC₅₀ values of 15.6 and 18.1 μM, respectively, and 2, 7, 9, and 11 showed inhibitory effect on influenza A virus with IC₅₀ values ranging from 12.4 to 18.9 μM.