Synthesis, in vitro anticancer screening and radiosensitizing evaluation of some new 4-[3-(substituted)thioureido]-N-(quinoxalin-2-yl)-benzenesulfonamide derivatives

Sulfonamides and quinoxaline derivatives possess many types of biological activities and have been recently reported to show substantial antitumor activity. This paper reports the synthesis of novel thioureido sulfaquinoxaline derivatives. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against a human liver cell line (HEPG2) and showed higher activity than the reference drug doxorubicin. 4-(3-(4-Ethylbenzoate) thioureido)-N-(quinoxalin-2-yl)benzenesulfonamide (9) (IC₅₀ = 15.6 μmol L^-1), N-(pyridin-2-yl)-4-(3-(4-(N-quinoxalin-2-yl-sulfamoyl)phenyl)thioureido)benzenesulfonamide (10) (IC₅₀ = 26.8 μmol L^-1) and N-(quinoxalin-2-yl)-4-(3-(4-(N-thiazol-2-ylsulfamoyl)phenyl)thioureido)benzenesulfonamide (11) (IC₅₀ = 24.4 μmol L^-1) were the most potent compared to doxorubicin (IC₅₀ = 71.8 μmol L^-1). The most potent compounds 9, 10 and 11 were evaluated as radiosensitizing agents by subjecting the compounds to γ-irradiation (8 kGy).