Antioxidant Flavone Glycosides from the Leaves of <i>Fargesia robusta</i>

The aqueous methanolic leaf extract of <i>Fargesia robusta</i> var. <i>Pingwu</i> was evaluated in vitro for its antioxidant capacity using the TEAC and ORAC assays. C-Glycosyl flavones, farobin A (<b>1</b>) and farobin B (<b>2</b>), together with three known compounds, tricin-5-<i>O</i>-glucopyranoside (<b>3</b>), 2′′-<i>O</i>-α-rhamnosyl-6-<i>C</i>-(6-deoxy-<i>ribo</i>-hexos-3-ulosyl)luteolin (<b>4</b>), and luteolin-6-<i>C</i>-glucopyranoside (homoorientin) (<b>5</b>), were isolated from the hydroalcoholic extract of the leaves of <i>F. robusta</i>. The structures of the compounds were determined by spectroscopic analyses including UV, 1D and 2D NMR, and MS. Compounds <b>1</b>, <b>4</b>, and <b>5</b> exhibited potent antioxidant activity in the TEAC assay, while compounds <b>1</b>, <b>3</b>, and <b>5</b> showed the highest antioxidant capacity in the ORAC assay.