ABSTRACTObjective: Aim of this work is to synthesize and characterization of the hydroxyl group the hydroxyl group substituted L-phenylalanine Schiff basesto compare their predicted quantitative structure-activity relationship (QSAR) and molecular docking against Escherichia coli protein ZipA (1s1j)outcomes with the antibacterial activity and brine shrimp lethal assay (BSLA) results.Methods: The Schiff bases of L-Phenylalanine were synthesized by the simple condensation reaction using methanol, water in 2:1 ratio at reflux andwere characterized by spectral techniques. QSAR parameters of the Schiff bases were predicted using java-based online and offline tools. Moleculardocking carried through online mcule server and CLC Drug Discovery Workbench 3. Antibacterial activity and toxicity studies were conducted usingbroth dilution and brine shrimp lethal assay methods, respectively.Results: The Schiff bases fulfilled the QSAR drug-likeness parameters and showed the docking score between −6.8 and −6.0 Kcal/mol which arehigher than amoxilicillin and gentamicin like standard drugs. They also possess good inhibition for urinary tract infection causing E. coli bacteria,and minimum inhibitory concentrations (MIC) exists between 3.25 and 5.25 μg/ml. The brine shrimp lethal concentration for 50% mortality [LC50])between 58.73 and 135.6 μg/ml.Conclusion: Para, meta and 2,4 hydroxyl substituted Schiff bases exhibited good inhibition against Gram-negative E. coli bacteria at low concentrationand the MIC exists below the LC50 value. The Schiff base showed high drug score, high docking score, and low toxicity than other Schiff base. Dockingscore, high inhibition, low clogP, low MICKeywords: L-phenylalanine, Schiff base, Quantitative structure-activity relationship, Docking, Antibacterial, Lethal concentration for 50% mortality.
High-valued Pyrazinoindole analogues: Synthesis, Antibacterial Activity, Structure Activity Relationship and Molecular Dynamics Analyses
