Two compounds, AM 58 (3) and AM 114 (8) were synthetized and, revealed cytotoxic activity against human colon carcinoma cells (HCT116 p53+/+ cells: 3, half maximal inhibitory concentration (IC50) of 3.85 μM; 8, IC50 of 1.49 μM) by inhibiting the 20S proteasome, which consequently resulted in an agglomeration of some ubiquitinated proteins and of p53. The gene discussed is TP53; the disease is colon carcinoma.