A new antioxidant flavone glycoside from <i>Scutellaria baicalensis</i> Georgi

<div><p>A new flavone glycoside, wogonin 7-<i>O</i>-β-d-ethylglucuronide (<b>1</b>), together with a new natural flavone glycoside baicalein 7-<i>O</i>-β-d-ethylglucuronide (<b>2</b>) and four known analogues, wogonoside (<b>3</b>), wogonin (<b>4</b>), oroxylin A 7-<i>O</i>-β-d-methylglucuronide (<b>5</b>) and oroxylin A (<b>6</b>), was isolated from the roots of <i>Scutellaria baicalensis</i> Georgi. The structure elucidation of the new compound was primarily based on HR-ESI-MS, 1D and 2D NMR analyses. Compounds <b>1</b> and <b>3</b> inhibited FeSO₄–Cys-induced liver homogenate lipid peroxidation with IC₅₀ at 18.2 μM and 24.9 μM, respectively, and exhibited strong cytoprotective effects against H₂O₂-induced oxidative damage in human umbilical vein endothelial cells at low concentrations of 10.0 μM and 3.0 μM.</p>