Preparation of ligands
The chemical structures of curcumin derivatives were constructed using Chem3D 15.0 module of ChemOffice 15.0 and saved in PDB format. The structures were optimized using “Prepare Ligands” in the AutoDock 4.2, flexible torsions were assigned and the acyclic dihedral angles were allowed to rotate freely. The file was then saved as pdbqt file format for further analysis.