Chemical constituents from the culture of the fungus Hericium alpestre

Two new compounds herialpins A–B (1–2), along with eleven known compounds, were isolated from the culture of fungus Hericium alpestre. The structures were elucidated by 1D and 2D NMR data, ESI-MS and X-ray crystallographic analysis. Compounds 1–2 were assayed for their cytotoxicity against three tumor cell lines compared with the known compound 3. Compounds 1 and 2 were found with modest activity, while compound 3 exhibits stronger selective inhibitory activity against A549 and HT-29 cells with IC₅₀ values of 15.1 and 20.1 μmol/L, respectively. The pyrano[3,4-g]chromene-4,6-dione moiety in compound 3 should be responsible for the stronger selective inhibitory activity.