New Spirostane from a Fungus Neohelicomyces hyalosporus and Its Bioactivity

A new spirostane, namely neohelicomyine B (1), together with six known steroids (2-7) were isolated from the fermentation of fungus Neohelicomyces hyalosporus. The structures of these compounds were elucidated by extensive analyses of spectroscopic methods including 1D and 2D NMR and HR-ESI-MS. The absolute configuration of 1 was confirmed by single-crystal X-ray diffraction. The bioactivities of compounds 1-7 were evaluated using cellular assays. Compound 1 displayed moderate cytotoxicity against HepG2 cells (hepatoma cells) with IC₅₀ value of 8.4±2.1 μM. Compound 7 also exhibited cytotoxic activity against HepG2 cells with the IC₅₀ value of 3.0±0.2 μM.