<p>This is the first study on the phytochemistry and antioxidant activity of <i>Ferula longipes</i> Coss. ex Bonnier and Maury (Apiaceae). A new flavonoid quercetin-3-<i>O</i>-<i>α</i>-L-rhamnopyranoside-7-O-<i>ß</i>-D-[2-O-caffeoyl]-glucopyranoside (<b>1</b>), along with 10 known compounds kaempferol-3-<i>O</i>-<i>α</i>-L-rhamnopyranoside (<b>2</b>), quercetin-3-<i>O</i>-<i>α</i>-L-rhamnopyranoside (<b>3</b>), kaempferol-3-<i>O</i>-<i>ß</i>-D-glucopyranoside-7-<i>O</i>-<i>α</i>-L-rhamnopyranoside (<b>4</b>), isorhamnetin-3-<i>O</i>-<i>α</i>-L-rhamnopyranoside-7-<i>O</i>-<i>ß</i>-D-glucopyranoside (<b>5</b>), quercetin-3-<i>O</i>-<i>α</i>-L-rhamnopyranoside-7-<i>O</i>-<i>ß</i>-D-glucopyranoside (<b>6</b>), isorhamnetin-3,7-di-<i>O</i>-<i>β</i>-D-glucopyranoside (<b>7</b>), apigenin (<b>8</b>), apigenin-7-<i>O</i>-<i>ß</i>-D-glucopyranoside (<b>9</b>), 3,5-dicaffeoylquinic acid (<b>10</b>), deltoin (<b>11</b>) were isolated from the aerial parts of <i>Ferula longipes</i> Coss. Structures elucidation was performed by comprehensive 1D and 2D NMR analyses, mass spectrometry and by comparison with literature data. The compounds <b>1</b>, <b>3</b>, <b>4</b>, <b>6</b>, <b>7</b> and <b>10</b> were evaluated for their antioxidant activity, compound <b>1</b> exhibited the best antiradical activity potential and showed IC<sub>50</sub> and A<sub>0.5</sub> values 5.70, 7.25, 5.00, and 2.63 μg/mL towards DPPH free radical-scavenging, ABTS, CUPRAC, and reducing power assays, respectively compared with BHA, BHT and ascorbic acid which were used as positive controls.</p
