Synthesis, characterization of 4,6-disubstituted aminopyrimidines and their sulphonamide derivatives as anti-amoebic agents

The present study describes the synthesis and anti-amoebic activity of 4,6-disubstituted aminopyrimidines (1b–10b) and their sulphonamide derivatives (1–20). All the desired compounds were characterized by spectral data and their purity was confirmed by elemental analysis. The aim of the study was to explore the effect of the target compounds on in vitro growth of HM1:IMSS strain of Entamoeba histolytica. In vitro anti-amoebic activity was performed by microdilution method and the results were compared with standard drug metronidazole. The results revealed that sulphonamide derivatives (1–20) showed better activity than 4,6-disubstituted aminopyrimidines (1b–10b). 5 pyrimidine and 12 sulphonamide derivatives were better inhibitors of the growth of E. histolytica than the reference drug metronidazole (IC50 = 1.80 μM). The promising in vitro anti-amoebic activity of the compounds make them promising molecules for further lead optimization in the development of novel anti-amoebic agents, therefore, it is hoped that these preliminary results could help in designing better molecules with an enhanced anti-amoebic activity.