Synthesis, Antimalarial Evaluation and SAR Study of Some 1,3,5-Trisubstituted Pyrazoline Derivatives

The synthesis of a novel series of 1,3,5-trisubstitiuted pyrazoline was achieved by refluxing chalcone derivative with different heteroaryl hydrazines. The newly synthesized compounds were characterized by 1H NMR, 13CNMR, mass spectral and elemental analysis data. The synthetic series of novel pyrazoline hybrids was screened for in vitro schizont maturation assay against chloroquine sensitive 3D7 strain of Plasmodium falciparum. Most of the compounds showed promising in vitro antimalarial activity against CQ sensitive strain. The preliminary structure-activity relationship study showed that quinoline substituted analog at position N-1 showed maximum activity followed by benzothiazole substitution, while phenyl substitution lowers the antimalarial activity. The observed activity was persistent by the docking study on P. falciparum cystein protease falcipain-2. The pharmacokinetic properties were also studied using ADME prediction.