Synthesis and Activity Evaluation of Novel Prenylated Flavonoids as Antiproliferative Agents

Twenty prenylated flavonoids 1-20 were synthesized by glycoside hydrolysis, dehydrogenation, selective O-methylation, O-prenylation and Claisen rearrangement reaction, from abundant and inexpensive natural flavonoids naringin, hespiredin, quercetin and myricetin. Among them, 1-7, 10-15 and 17-20 are novel compounds, the natural product 3,3',4',7-tetramethoxy-8-prenyl-5-hydroxy flavonoid(16) was synthesized in a high yield. Their antiprolirative activities were evaluated in vitro on a panel of three human cancer cell lines(HeLa, HCC1954 and SK-OV-3). The results show that most of the target compounds displayed moderate to potent antiprolirative activities against the three cancer cells with half maximal inhibitory concentration(IC₅₀) values from 0.49 μmol/L to 95.07 μmol/L. Among them, 3',4',7-trimethoxyl-5-hydroxyl-8-prenyl flavonoid(12) exhibited the strongest antiprolirative activity against the three cancer cells mentioned above with IC₅₀ values of 0.91-7.08 μmol/L. 3',7-Dimethoxy-5-O-prenyl flavone(6) and 3',4',7-trimethoxy-5-O-prenyl flavone(10) showed selective antiproliferative activity against HCC1954 cells with IC₅₀ value of 0.49 and 5.32 μmol/L, respectively.