Two new phenolic constituents of Humulus japonicus and their cytotoxicity test in vitro.

Two new phenolic constituents (4 and 6), together with four known constituents, methyl ferulate (1), eugenyl-beta-D-glucopyranoside (2), apigenin-7-O-beta-D-glucopyranoside (3), and (E)-resveratrol-3-O-beta-D-glucopyranoside (5) were isolated from the MeOH extract of the aerial part sof Humulus japonicus. The structures of the new compounds were determined by spectroscopic methods to be divarin-3-O-beta-glucopyranoside (4), and lariciresinol-9-O-beta-xylopyranoside (6). Compounds 1 and 3 exhibited moderate cytotoxicity against two human cancer cell lines (SK-OV-3 and HCT15) with ED50 values ranging from 8.84 to 8.79 microM.