Synthesis, molecular docking, antimicrobial, antioxidant and toxicity assessment of quinoline peptides

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 178; pp. 287 - 295
• Main Authors: Thangaraj, Muthu, Gengan, Robert Moonsamy, Ranjan, Bibhuti, Muthusamy, Ramesh
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01-01-2018; Elsevier BV
• Subjects: Aniline; Antiinfectives and antibacterials; Antimicrobial; Antimicrobial agents; Antioxidant; Antioxidants; Bacterial infections; Chemical synthesis; Ciprofloxacin; Condensates; Data processing; Deoxyribonucleic acid; Derivatives; DNA; DNA topoisomerase; E coli; Irradiation; Libdock; Lipoic acid; Molecular docking; NMR; Nuclear magnetic resonance; Optimization; Peptides; Quinoline; Saline water; Toxicity; Toxicity testing; Ugi reaction; Antimicrobial; Quinoline; Libdock; Peptides; Antioxidant; Ugi reaction
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2017.11.019

A series of quinoline based peptides were synthesized by a one-pot reaction through Ugi-four component condensation of lipoic acid, cyclohexyl isocyanide, aniline derivatives and 2-methoxy quinoline-3-carbaldehyde derivatives under microwave irradiation. The products were obtained in excellent yields and high purity. Solvent optimization and the effect of microwave irradiation with various powers were also observed. All the synthesized compounds were characterized by FTIR, NMR spectral data and elemental analysis. A total of eight peptides were subjected to antimicrobial, antioxidant and toxicity evaluation. Among them, four peptides showed potential towards antibacterial screening with Bacillus cereus, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis and Candida albicans, Candida utilis and three peptides showed antioxidant test positive (DPPH). Besides, toxicity of all the peptides were evaluated by using brine shrimp and it was observed that four peptides showed mortality rate less than 50% up to 48h. Molecular docking studies revealed that the higher binding affinity of the two peptides toward DNA gyrase than ciprofloxacin based on Libdock score. The described chemistry represents a facile tool to synthesize complex heterocycles of pharmaceutical relevance in a highly efficient and one-pot fashion. The advantages of this method are its green approach, inexpensive solvent, shorter reaction times and excellent yields.
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•A series of quinoline peptides were synthesized under microwave irradiation.•All the compounds were explained by IR, 1H NMR, 13C NMR and elemental analysis.•90% yield was obtained in 15min with excellent purity.•Antimicrobial, antioxidant and toxicity assessment of the peptides were reported.•Molecular docking studies were done for the peptides based on Libdock score.