EXTRACTION AND ISOLATION OF FLAVONOID QUERCETIN FROM THE LEAVES OF TRIGONELLA FOENUM-GRAECUM AND THEIR ANTI-OXIDANT ACTIVITY

Objective: The present study was designed for isolation of bioactive flavonoid molecule quercetin from the leaves of Trigonella foenum-graecum and their subsequent characterization. Methods: Crude extracts of fenugreek were prepared using various solvents such as hexane, ethyl acetate, and ethanol. The plant extracts were subjected for photochemical analysis and total flavonoid content. The extracts were then subjected to column chromatography followed by TLC. The isolated compound was subjected to FT-IR, 1 H NMR, 13 C NMR, mass spectroscopy and their free radical scavenging activity was studied. Results: The ethanol extract showed the presence of higher flavonoid content when compared with other solvent extracts. The ethanol extract was subjected to fractionalization by column chromatography. The eluted fractions were run in TLC mobile phase with the different solvent ratio. The fractions showed R f value equal to standard quercetin in TLC were combined and crystallized. The characterization techniques confirmed that the isolated compound was found to be quercetin. The free radical scavenging activity suggests that the isolated compound quercetin could act as a potent source of antioxidants. Conclusion: The flavonoid quercetin was isolated effectively from the leaves of Trigonella foenum-graecum and their antioxidant activity was studied. Keywords: Antioxidant activity, DPPH, Flavonoids, NMR, Quercetin