Novel aryl carbamate derivatives of metronidazole as potential antiamoebic agents

A series of novel aryl carbamate derivatives of metronidazole (MNZ) were designed, synthesized, and screened for antiamoebic activity. As compared to MNZ, most of the derivatives exhibited moderate to excellent activity against the HM1:IMSS strain of Entamoeba histolytica. Compounds 7, 14, 16, 19, and 21 exhibited the most promising antiamoebic activity with IC50 values of 0.24, 0.08, 0.26, 0.26, and 0.15 mu M, respectively, compared to that of MNZ (1.78 mu M). Moreover, from the toxicological studies of these compounds on human melanocytes, the melan-a cell line revealed that the potent compounds are nontoxic at concentrations ranging from 2.5 to 50 mu M.