Identification of an anticancer compound against HT-29 cells from Phellinus linteus grown on germinated brown rice

Objective To isolate and identify the anticancer compound against proliferation of human colon cancer cells from ethyl acetate (EtOAc) extract of Phellinus linteus grown on germinated brown rice (PB). Methods EtOAc extract of PB was partitioned with n-hexane, EtOAc, and water-saturated n-butanol. Anticancer compound of n-hexane layer was isolated and identified by HPLC and NMR, respectively. Cytotoxicity against HT-29 cells was tested by SRB assay. Results The n-hexane layer obtained after solvent fractionation of PB EtOAc extracts showed a potent anticancer activity against the HT-29 cell line. Atractylenolide I, a eudesmane-type sesquiterpene lactone, a major anticancer substance of PB, was isolated from the n-hexane layer by silica gel column chromatography and preparative-HPLC. This structure was elucidated by one- and two-dimensional NMR spectroscopic data. Atractylenolide I has not been reported in mushrooms or rice as of yet. The isolated compound dose-dependently inhibited the growth of HT-29 human colon cancer cells. Conclusions Atractylenolide I might contribute to the anticancer effect of PB.