摘要：Ergosterol peroxide (EPO, 1) is a major antitumor sterol produced by edible or medicinal mushrooms. Following oral administration of 1 to rats or anaerobic in vitro incubation of 1 with rat fecal bacteria, three metabolites were detected and their structures were identified to be 5α,6α-epoxyergosta-8(14),22-diene-3β,7α-diol (M1, 2), 5α,6α-epoxyergosta-8,22-diene-3β,7α-diol (M2, 3), and 5α,6α-epoxy-3β-hydroxyergosta-22-ene-7-one (M3, 4) by spectroscopic analysis. Of these, M2 and M3 showed more potent inhibitory activity than the original compound 1 against proliferation of CACO-2, WiDr, DLD-1 and Colo320 human colorectal adenocarcinoma cells. These findings suggest that bacterial metabolites of EPO play a significant role in its cytotoxic activity against human colorectal cancer cells.
