Herein, the compounds bearing sulfonamide fragment such as N-(2-amino-5-benzoylphenyl)-4-nitrobenzene sulfonamide hydrochloride (1), N-(quinolin-8-yl)-4-nitro-benzenesulfonamide hydrochloride (2), N-(pyridine-2-ylmethyl)-4-nitro-benzenesulfonamide hydrochloride (3) were synthesized by the reaction of 3,4-diaminobenzophenone, 8-aminoquinoline or 2-picoylamine and 4-nitrobenzensulfonyl chloride, respectively. The structures of the newly synthesized compounds were elucidated on the basis of elemental and spectral analyses. All the prepared compounds were evaluated for their in vitro anti-cancer activity against various cancer cell lines and to explore the underlying molecular mechanisms involved in this process. In vitro cytotoxic activities of the compounds were screened against human hepatocellular (HepG2), breast (MCF-7) and colon (Colo-205) cancer cell lines by MTT assay, mRNA expression of genes with qPCR and phosphorylation of p38 and ERK1/2 with Western blot. Tested compounds could significantly reduce cell proliferation and induced mRNA expression of pro-apoptotic genes; caspase 3, caspase 8 and caspase 9. Activation of these apoptotic genes probably is mediated by activation of p38.