Synthesis and antiproliferative effect of novel curcumin analogues.

Novel curcumin analogues with α,β-unsaturated ketone moiety and/or α,β-saturated ketone structure were synthesized from curcumin via alkylation at the central carbon and the phenolic hydroxy groups, and hydrogenation of α,β-unsaturated ketone moiety. The antiproliferative activities were tested in five human solid tumor cell lines in vitro. Most of the compounds exhibited increased antiproliferative activities comparing with that of curcumin. Structure-activity relationship (SAR) analysis revealed that the α,β-unsaturated ketone structure was not required for antiproliferative activity of these curcumin analogues. Among these compounds, 1,7-bis(3-methoxy-4-(3-(4-methylpiperazinyl-1-yl)propoxy)phenyl)-4,4-dibenzylheptane-3,5-dione (16f) was the most effective one with IC50 value below 1 µM, which was 9- to 81-fold more potent than curcumin.