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 MU-based assay. Compared with the posit...