Efficient synthesis and antiproliferative activity of novel thioether-substituted flavonoids.

As widely occurring natural products, flavonoids are an important source for drug discovery, due to their structural diversity and broad-spectrum biological activity. In this work, a library of novel, thioether-substituted flavonoids with diverse heterocyclic groups was synthesized via a microwave-assisted procedure with the advantages of good yields, short times, mild conditions and ready isolation of the products. Their antiproliferative activities were evaluated against six cancer cell lines, HCCLM-7, Hela, MDA-MB-435S, SW-480, Hep-2, and MCF-7 by the MTT-based assay. Compared with the positive control 5-fluorouracil, three compounds, 6a, 6b and 6j were successfully identified as the most promising candidates, due to their higher potency and broad-spectrum bioactivity with IC50 values in the range of 0.43 μM-6.7 μM.