Synthesis and antitumor evaluation of some new 1,3,4-oxadiazole-based heterocycles

The synthetic strategies and characterization of some novel 1,3,4-oxadiazole derivatives carrying different pharmacophores and heterocyclic rings that are relevant to potential antitumor and cytotoxic activities are described. The antitumor activities of the newly synthesized compounds were evaluated according to the protocol of the National Cancer Institute (NCI) in-vitro disease-oriented human cells screening panel assay. The results revealed that five compounds, namely 2, 7a, 11a, 12b, and 17; displayed promising in-vitro antitumor activity in the 4-cell lines assay. Incorporating a thiazole ring to 1,3,4-oxadiazole skeleton resulted in better antitumor activities than those displayed by the pyrazole and thiophene ring systems. Transformation of 1,3,4-oxadiazole 2 to N-(6-amino-7H-pyrazolo[5,1-c][1,2,4]triazol-3-yl)benzamide (15) diminished the antitumor activity.

Graphical abstractA novel series of 1,3,4-oxadiazole-based heterocycles were synthesized to evaluate their antitumor activity.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A new series of 1,3,4-oxadiazole-based heterocycles were synthesized. ► The antitumor activity of new compounds have been screened. ► Compounds 2 and 7a showed the strongest antitumor activity. ► The thiazolyloxadiazole skeleton is decisive in developing a new antitumor agent. ► Compounds 2 and 7a showed also high protection against DNA damage.