Synthesis and biological evaluation of novel disulfides incorporating 1,3,4-thiadiazole scaffold as promising antitumor agents

In the present study, fourteen 2,5-disubstituted 1,3,4-thiadiazole derivatives containing disulfide group were prepared. The resulting compounds 7a–7n were identified by IR, NMR, MS, and elemental analysis. Their antiproliferative properties in vitro were studied employing standard CCK-8 assay against SMMC-7721, MCF-7, and A549 lines. Bioassay indicated that some compounds showed stronger antitumor effects than reference drugs PX-12 and 5-fluorouracil. Among these screened compounds, compound 7h showed excellent biological activities in inhibiting SMMC-7721 cell proliferation with IC50 at 1.93 ± 0.08 μM. Compounds 7k and 7i manifested highly effective growth inhibitory activity versus MCF-7 cells, with IC50 at 3.04 ± 0.09 and 3.54 ± 0.17 μM, respectively. For A549 cells, compound 7m was found to have the highest antitumor potency with IC50 at 3.67 ± 0.13 μM.