Chalcone (1,3-diphenylprop-2-en-1-one) compounds are of natural or synthetic origins and posess a diversity in bioactivities. Recently, the inhibitory activities of heterocylic chalcones against differerent cancer cell lines have raised much concern. 

The study aimed at synthesizing some heterocylic chalcones and determining their in vitro cytotoxicity on rhabdomyosarcoma (RD) cell line. 

Heterocyclic chalcones in this study were developed on the basis of the idea that heteroaryl moieties either on ring A or ring B of chalcones might provide cytotoxicity on cancer cells. These compounds were prepared by Claisen-Schmidt condensation The in vitro cytotoxicity of the compounds on rhabdomyosarcoma (RD) cell line has been evaluated using the microculture tetrazolium (MTT) assay. 

A total of synthesized heterocyclic chalcones has been synthesized and their structures were elucidated by spectrometric methods. Bioassay results revealed that 5 out of 20 compounds showed activities against RD cells with IC₅₀ values less than 20μM. Notably, cytotoxicity of (E)-1-(thiophen-2-yl)-3-(3,4,5-trimethoxy-phenyl)prop-2- en-1-one increased with decreasing concentration. It was showed as the most potential compound with IC₅₀ at 12.51 μM (compare with taxol IC₅₀ at 10.88μM).

The results demonstrate that heterocylic chalcones are promising compounds for developing anticancer drugs.