Anti-Xanthine Oxidase 5-Hydroxyhericenes A-D from the Edible Mushroom Hericium erinaceus and Structure Revision of 3-[2,3-Dihydroxy-4-(hydroxymethyl)tetrahydrofuran-1-yl]-pyridine-4,5-dio l

Hericium erinaceus is an edible mushroom with diverse pharmaceutical applications. Although this mushroom is an attractive source of natural products for cancer treatment, little is known about the bioactive compounds from this mushroom, which may possess antibreast cancer activity. Here, we report the isolation and structure elucidation of new compounds, 5 '-hydroxyhericenes A-D (1-4) as an inseparable mixture, together with known compounds (5-16) from the fruiting body of H. erinaceus. Based on NMR spectroscopic data and MS fragmentation analysis, the structure of a previously reported natural product, 3-[2,3-dihydroxy-4-(hydroxymethyl)-tetrahydrofuran-1-yl]-pyridine-4,5-diol (5), should be revised to adenosine (6). Compounds 1-4 inhibit xanthine oxidase activity, while compounds 6, 9, and 10 scavenge reactive oxygen species generated by xanthine oxidase. Moreover, hericerin (13) exhibits strong growth inhibitory activity against T47D breast cancer cells and, to a lesser extent, against MDA-MB-231 breast cancer and MRC-5 normal embryonic cells. Exposure of T47D and MDA-MB-231 cells slightly increased PARP cleavage, suggesting that the growth inhibitory effect of hericerin may be mediated through nonapoptotic pathways. Our results suggest that the bioactive compounds of mushroom H. erinaceus hold promise as antibreast cancer agents.