HPLC-UV-Guided isolation of Phenylspirodrimanes from Stachybotrys sp

HPLC-UV-Guided chemical investigation into a soil-derived Stachybotrys species led to the isolation of two new phenylspirodrimanes (1 and 2), two new natural products (3 and 4), and six known compounds. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of 6 was confirmed unambiguously by single-crystal X-ray diffraction analysis. Compounds 1-3 and 5-9 were evaluated for their cytotoxic activity against five human tumor cell lines. As a result, compounds 1, 2, 5, 8, and 9 showed significant to moderate cytotoxicity to all or some of the tumor cell lines with IC₅₀ values in the range of 12.71-25.51 μM.