Twenty-one new chalcones 9a-m (excluding 9e, 9j and 9l) and 10a-m (excluding 10j and 10l), containing nucleobases were synthesized from 2'-hydroxyacetophenone (1) by the reactions including chloromethylation, nucleophilic substitution with thymine and uracil, and Claisen-Schmidt reactions. These new chalcones were evaluated for in vitro cytotoxicity against five human cancer cell lines: SK-LU-1, Hep-G2, MCF7, SW480 and P388. The ...