<jats:title>Abstract</jats:title><jats:p>A new quinonemethide triterpene named as salacin, has been isolated from the root bark of <jats:italic>Salacia campestris</jats:italic> in addition to the known pristimerin, maytenin, 20<jats:italic>α</jats:italic>‐hydroxymaytenin, and netzahualcoyene. Salacin was identified on the basis of NMR‐spectral and mass spectrometric analysis. The free‐radical scavenging activities of the quinonemethide triterpenes salacin (<jats:bold>1</jats:bold>), pristimerin (<jats:bold>2</jats:bold>), maytenin (<jats:bold>3</jats:bold>), 20<jats:italic>α</jats:italic>‐hydroxymaytenin (<jats:bold>4</jats:bold>), and netzahualcoyene (<jats:bold>5</jats:bold>) towards DPPH have been evaluated and showed absorbance variation (Δ<jats:italic>A</jats:italic>) of 19, 20, 39, 28, 55, and 10%, respectively, having rutin (74% at 50 μ<jats:sc>M</jats:sc>) and BHT (7% at 50 μ<jats:sc>M</jats:sc>) as standard compounds.