Mannich base derivatives of 1,3,4-oxadiazole: synthesis and screening against Entamoeba histolytica

Mannich base derivatives of 5-(pyridine-4-yl)-1,3,4-oxadiazole-2-(3H)-thione with substituted piperazine were synthesized and characterized. In vitro antiamoebic activity was performed against HM1: IMSS strain of Entamoeba histolytica and the cytotoxicity of the compounds having IC50 value less than metronidazole was assessed by MTT assay on human breast cancer MCF-7 cell line. The results revealed that compounds 2, 3 and 5 were found to be better inhibitors of E. histolytica than the reference drug metronidazole and found low cytotoxic in the concentration range of 2.5–250 μM. This study suggests the possibility of developing 1,3,4-oxadiazole analogues as potential drug candidates.