<jats:title>Abstract</jats:title><jats:p>The fruit of <jats:italic>Tetradium ruticarpum</jats:italic> is widely used in healthcare products for the improvement of blood circulation, headache, abdominal pain, amenorrhea, chill limbs, migraine, and nausea. A new quinolone, 2‐[(6<jats:italic>Z</jats:italic>,9<jats:italic>Z</jats:italic>)‐pentadeca‐6,9‐dienyl]quinolin‐4(1<jats:italic>H</jats:italic>)‐one (<jats:bold>1</jats:bold>), has been isolated from the fruits of <jats:italic>T. ruticarpum</jats:italic>, together with eleven known compounds. The structure of the new compound was determined by NMR and MS analyses. Rutaecarpine (<jats:bold>4</jats:bold>), evodiamine (<jats:bold>5</jats:bold>), and skimmianine (<jats:bold>7</jats:bold>) exhibited inhibition (<jats:italic>IC</jats:italic><jats:sub>50</jats:sub>≤20.9 μ<jats:sc>M</jats:sc>) of O<jats:styled-content>$\rm{{_{2}^{{^\cdot} -}}}$<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/tex2gif-ueqn-1.gif" xlink:title="equation image" /></jats:styled-content> generation by human neutrophils in response to <jats:italic>N</jats:italic>‐formyl‐<jats:sc>L</jats:sc>‐methionyl‐<jats:sc>L</jats:sc>‐leucyl‐<jats:sc>L</jats:sc>‐phenylalanine/cytochalasin B (fMLP/CB). In addition, <jats:bold>1</jats:bold>, evocarpine (<jats:bold>2</jats:bold>), <jats:bold>4, 7</jats:bold>, and evodol (<jats:bold>8</jats:bold>) inhibited fMLP/CB‐induced elastase release with <jats:italic>IC</jats:italic><jats:sub>50</jats:sub> values ≤14.4 μ<jats:sc>M</jats:sc>.