α-Tetralonyl Glucosides from the Green Walnut Husks of Juglans mandshurica and Their Antiproliferative Effects

Two new α-tetralonyl glucosides, (4S)-4,5,8-trihydroxy-α-tetralone-5-O-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranoside (1) and (4S)-4,8-dihydroxy-α-tetralone-4-O-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranoside (2), together with eight known compounds (3 – 10) were isolated from the green walnut husks of Juglans mandshurica. The structural characterization of all compounds was performed by spectroscopic analyses, including 1D and 2D NMR and HR-ESI-MS experiments. The isolated compounds were assayed for their cytotoxicity against two human cancer cell lines, A549 and HeLa. Four compounds (7 – 10) exhibited inhibitory effects against two human cancer cell lines with GI50 values between 1.3 and 5.8 µM.