Isolation of a free radical-scavenging antioxidant from water spinach (Ipomoea aquatica Forsk)

<p align="justify">Ipomoea aquatica Forsk, a green leafy vegetable that is a rich source of vitamins and amino acids
with many health benefits, has been explored for the isolation and identification of its bioactive compounds.
Activity-guided repeated fractionation of a methanol extract on a silica gel column followed by an XAD
column yielded a compound that exhibited antioxidant activity with an EC50 value of 83 ± 1.02 µgml−1
reaction mixture. It also showed very strong lipid peroxidation-inhibitory activity in a liposome
model system with an EC50 value of 72.2 ± 0.9 µgml−1. However, it showed negligible metal-chelating
activity. Based on UV, 2D nuclear magnetic resonance and gas chromatography/mass spectrometry
studies, the compound was tentatively identified to be 7-O-β-D-glucopyranosyl-dihydroquercetin-3-O-α-
D-glucopyranoside. This is the first report on the antioxidant properties of I aquatica leaf extracts.
 2005 Society of Chemical Industry</p>