Synthesis of Oxoquinoline Derivatives Coupled to Different Amino Acid Esters and Studying Their Biological Activity as Cytotoxic Agents

Abstract

Objectives: Quinolines are an important group of organic compounds where several compounds containing a quinoline residue are known to possess useful biological activity and used as antibacterial, antifungal and antitumor agents. These pharmacological properties of quinolines aroused our interest in synthesizing several new compounds featuring heterocyclic rings of the quinoline derivatives linked to amino acid ester side chains with the aim of obtaining a pharmacologically active compounds Methods: Quinoline was N-alkylated by the bromoacetic acid and then oxidized with an alkaline potassium ferricyanide solution to get N-alkylated quinolone. Conventional solution method for peptide synthesis used as a coupling method between the carboxy-protected amino acids with the acetic acid side chain of quinolone. The DCC/HOBt coupling reagents used for the peptide bond formation. Results: The proposed analogues were successfully synthesized and their structural formulas were consistent with the proposed structures as they were characterized and proved by thin layer chromatography (TLC), melting point, infrared spectroscopy (IR) and elemental microanalysis. All tested analogues showed cytotoxic activity on the HEp-2 cell line (tumor of larynx) with inhibitory concentration percent of (IC%) range (49.01%-77.67%). Conclusion: It can be concluded from the results that the synthesized compounds are promising as new anticancer agents in future.