Xanthohumol D, isolated from hops, is an inhibitor of quinone reductase-2 (QR-2) with the IC50 value of 110 μM, and binds to the active site of QR-2. Xanthohumol D shows antiproliferative activity on human cancer cell lines in vitro[1][2]. IC50: 110 μM (Quinone reductase-2)[1]
[1]. Choi Y, et al. Screening natural products for inhibitors of quinone reductase-2 using ultrafiltration LC-MS. Anal Chem. 2011 Feb 1;83(3):1048-52. [2]. Tronina T, et al. Fungal metabolites of xanthohumol with potent antiproliferative activity on human cancer cell lines in vitro. Bioorg Med Chem. 2013 Apr 1;21(7):2001-6.