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.