Synthesis and evaluation of antioxidant activity of new quinoline-2-carbaldehyde hydrazone derivatives: bioisosteric melatonin analogues

Abstract

Overproduction of reactive oxygen species results in oxidative stress that can cause fatal damage to vital cell structures. It is known that the use of antioxidants could be beneficial in the prevention or delay of numerous diseases associated with oxidative stress. Melatonin (MLT) is known as a powerful free-radical scavenger and antioxidant. It was found that indole ring of MLT can be employed by bioisosteric replacement by other aromatic rings. Quinoline derivatives constitute an important class of compounds for new drug development. Owing to quinoline and hydrazones appealing physiological properties and are mostly found in numerous biologically active compounds a series of quinoline-2-carbaldehyde hydrazone derivatives were synthesized as bioisosteric analogues of MLT, characterized and in vitro antioxidant activity was investigated by evaluating their reducing effect against oxidation of a redox-sensitive fluorescent probe. Cytotoxicity potential of all compounds was investigated both by lactate dehydrogenase leakage assay and by MTT assay.

• Antioxidant
• hydrazone
• lactate dehydrogenase leakage
• melatonin
• MTT
• quinoline

Declaration of interest

The authors report no conflicts of interest. The chemical compounds of this work were supported by The Scientific and Technological Research Council of Turkey (TÜBİTAK) Research and Development Grant 112S599. The cell culture facility was established by the support of TUBITAK 108S202 Grant.