New 2-alkylthio-4-chlorobenzenesulfonamide derivatives bearing heterocyclic moieties – synthesis, structure and anticancer activity studies

Abstract

According to statistics, in 2012, there were estimated 1.4 million new colorectal cancer cases and 693,900 deaths. Breast cancer, the leading cause of cancer-related death among females worldwide, gave an estimated 1.7 million cases and 521,900 deaths in 2012. An estimated 527,600 cancer cases and 265,700 deaths in 2012 worldwide were caused by cervical cancer which is the third leading cause of cancer-related death in females [1]. Chemotherapeutics play an important role as anticancer agents, inducing apoptosis or restoring apoptotic functions of proteins. In view of the importance of sulfonamides and nitrogen containing heterocycles as privileged structures for designing anticancer agents, we decided to explore the synthesis and anticancer activity of molecular hybrids obtained by the combination of benzenesulfonamide and heterocycles such as imidazole, 1,2,4-triazole, benzimidazole and benzoxazole. The anticancer activities of compounds were evaluated in vitro on MCF-7, HCT-116 and HeLa human tumor cell lines by MTT assay. The most active compounds bearing 3-methyl-2-thioxo-1H-imidazol-1-yl moiety exhibited selectivity against HeLa cells with IC50 values 6‒7 µM. Meanwhile, 2-thioxo-1H-benzo[d]imidazole derivatives showed activity against HCT-116 cells in the range of IC50: 17‒36 µM. The apoptotic potential of the most active compounds was analyzed through various assays in HeLa cells: phosphatidylserine translocation, cell cycle dystribution and caspase activation. Results indicated that compounds promoted cell cycle arrest at sub-G1 phase in cancer cells, induced caspase activity and increased the population of apoptotic cells. [1] Torre L.A. et. al. Cancer Epidemiol. Biomarkers Prev. 25 (2016) 16‒27.