Synthesis, molecular docking and characterization of pyrazole N-mannich base derivatives as antimicrobial agents

In this work we aimed to design synthesis and evaluate the N-Mannich bases of pyrazole. A novel series of N-Mannich bases of pyrazole analogues were designed and synthesized with an effort to overcome the increasing antibiotic resistance. Tyrosyl-tRNA synthetase (TyrRS) comprises an N-terminal domain, which has the fold of the class I aminoacyl-tRNA synthetases. Computational Autodock 4.2 tools will be employed in this study for docking of pyrazole ligand molecules against Tyrosyl-tRNA synthetase (TyrRS) of Escherichia coli (PDB code: 1x8x) and Staphylococcus aureus (PDB code: 1jil.pdb). Molinspiration server was used for lead optimization. The ligand molecules were subjected to molecular docking studies with enzyme Tyrosyl-tRNA synthetase. The molecular docking studies are supported to compare in-vitro antibacterial activity by the use of binding energy of the docked ligand molecules. The newly synthesized compounds were characterized by UV, IR and various physico-chemical methods. Further, the antibacterial activity of N-Mannich bases of pyrazole compounds were assessed with zone of inhibition by agar well diffusion method using gram negative bacterial strain Escherichia coli and gram-positive strain staphylococcus aureus. These same compounds were subjected to find the antifungal activity against Aspergillus fumigates and Aspergillus Niger.