The Synthesis and Antitumor Activity of Twelve Galloyl Glucosides

Twelve galloyl glucosides 1–12, showing diverse substitution patterns with two or three galloyl groups, were synthesized using commercially available, low-cost d-glucose and gallic acid as starting materials. Among them, three compounds, methyl 3,6-di-O-galloyl-α-d-glucopyranoside (9), ethyl 2,3-di-O-galloyl-α-d-glucopyranoside (11) and ethyl 2,3-di-O-galloyl-β-d-glucopyranoside (12), are new compounds and other six, 1,6-di-O-galloyl-β-d-glucopyranose (1), 1,4,6-tri-O-galloyl-β-d-glucopyranose (2), 1,2-di-O-galloyl-β-d-glucopyranose (3), 1,3-di-O-galloyl-β-d-glucopyranose (4), 1,2,3-tri-O-galloyl-α-d-glucopyranose (6) and methyl 3,4,6-tri-O-galloyl-α-d-glucopyranoside (10), were synthesized for the first time in the present study. In in vitro MTT assay, 1–12 inhibited human cancer K562, HL-60 and HeLa cells with inhibition rates ranging from 64.2% to 92.9% at 100 μg/mL, and their IC(50) values were determined to be varied in 17.2–124.7 μM on the tested three human cancer cell lines. In addition, compounds 1–12 inhibited murine sarcoma S180 cells with inhibition rates ranging from 38.7% to 52.8% at 100 μg/mL in the in vitro MTT assay, and in vivo antitumor activity of 1 and 2 was also detected in murine sarcoma S180 tumor-bearing Kunming mice using taxol as positive control.