Synthesis, characterization and in vitro anti-amoebic activity of new palladium(II) complexes with 5-nitrothiophene-2-carboxaldehyde N(4)-substituted thiosemicarbazones Original Research Article

Reaction between [Pd(DMSO)2Cl2] (DMSO = dimethylsulfoxide) and N4-substituted thiosemicarbazones derived from 5-nitrothiophene-2-carboxaldehyde (L) afforded the complexes [Pd(L)Cl2]. These new complexes have been characterized by elemental analyses and spectroscopic studies. Spectroscopic studies reveal that thionic sulfur and azomethine nitrogen atom of thiosemicarbazones are coordinated to metal ion. The testing of the anti-amoebic activity of these complexes against the protozoan parasite Entamoeba histolytica suggests that compound 9, 10, and 11 might be endowed with important anti-amoebic properties since they showed less IC50 values than metronidazole. Moreover, compound 11 displays notable amoebicidal activity than metronidazole (IC50 values of 0.79 μM vs 1.93 μM, respectively).