Synthesis, characterization and study of antioxidant activity of quercetin–magnesium complex

Quercetin (3,3′,4′,5,7-pentahydroxyflavone) one of the most abundant dietary flavonoids, has been investigated in the presence of magnesium (II) in methanol. The complex formation between quercetin and magnesium (II) was examined under UV–visible, Infra-red and 1H NMR spectroscopic techniques. The spectroscopic data denoted that quercetin can reacts with magnesium cation (Mg+2) through the chelation site in the quercetin molecule. The free radical antioxidant activity of the complex with respect to the parent molecule was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. It was observed that the free radical scavenging activity of quercetin was increased after complexation of magnesium (Mg+2) cation.