Synthesis and Antitumor Activities of 1,3,4-Thiadiazole Derivatives Possessing Benzisoselenazolone Scaffold

A series of novel 1,3,4-thiadiazole derivatives possessing benzisoselenazolone scaffold were designed and synthesized, and their antitumor activities against human cervix adenocarcinoma（HeLa）, human liver cancer cell（SMMC-7721）, human breast cancer cell（MCF-7） and human lung cancer cell（A549） lines were evaluated by CCK-8 assay, The bioassay results demonstrate that most of the tested compounds showed potent antiproliferative effects against various cell lines. Furthermore, compounds 7c, 7e, 7h, 7i and 7k showed significant antiproliferative activities against SMMC-7721 cells, with IC5o values of 2.38, 2.67, 1.35, 2.75 and 2.48 μmol/L, respectively. Com- pounds 7a, 7e, 7j and 71 exhibited highly effective antitumor activities against MCF-7 cells, with IC50 values of 2.89, 2.95, 1.12 and 2.75 μmol/L, respectively. Compound 7j was found to be the most potent compound against A549 cells, with an IC50 value of 1.25 μmol/L. The pharmacological results suggest that the substituents of benzylthio-moiety at position 2 on 1,3,4-thiadiazole are vital for modulating antitumor activities against various cancer cell lines.