Pyridine Based Chalcones: Synthesis and Evaluation of Antioxidant Activity of 1-Phenyl-3-(pyridin-2-yl)prop-2-en-1-one Derivatives

Background: Natural chalcones and also their synthetic derivatives have attracted increasing attention due to various pharmacological applications. Development and discovery of new chalcones with antioxidant activities is one of the attracting areas in medicinal and natural product chemistry. Objectives: In the present study, a new series of pyridine based chalcones was synthesized and their antioxidant capacity was evaluated by beta carotene bleaching (BCB), DPPH free radical scavenging, ferrous ion chelating (FIC) activity and Trolox equivalent antioxidant capacity (TEAC) methods. Materials and Methods: All compounds were synthesized via an aldol condensation procedure in methanol or ethanol solvent at room temperature and characterization was carried out by 1HNMR, IR and MS spectroscopic methods. Related melting points were also measured for each compound. Results: Fortunately, compounds 3e (16.53 ± 1.21 μg/mL), 3g (58.85 ± 1.10 μg/mL) and 3i (58.73 ± 12.94 μg/mL) showed higher antioxidant activity (EC50 ± SD) in comparison with quercetin (87.24 ± 3.93 μg/mL) as reference agent in ferrous ion chelating method. Furthermore, compounds 3g (4.82 ± 0.11 μg/mL) and 3h (6.33 ± 0.30 μg/mL) also exhibited an acceptable antioxidant property compared to Trolox (3.83 ± 0.22 μg/mL) in TEAC method. None of synthesized compounds demonstrated significant antioxidant activity in DPPH free radical scavenging as well as beta carotene bleaching tests. Conclusions: According to the obtained data, synthesized pyridine based chalcones (3a-3j) could be proposed as potential antioxidant lead compounds.