| সংক্ষিপ্ত: | As a traditional medicine with potential antioxidant effects, <i>Tenodera angustipennis</i> egg cases (Mantidis ootheca) are a potential source of new bioactive substances. Herein, three new <i>N</i>-acetyldopamine derivatives, namely, (+)-tenoderin A (<b>1a</b>), (−)-tenoderin A (<b>1b</b>), and tenoderin B (<b>2</b>), along with thirteen known compounds (<b>3</b>–<b>15</b>), were isolated from a 70% EtOH extract of <i>T</i>. <i>angustipennis</i> egg cases. Compound <b>1</b> was isolated as a racemic mixture, and two enantiomers (<b>1a</b> and <b>1b</b>) were successfully separated by chiral-phase preparative HPLC. The chemical structures of the new compounds were established by NMR spectroscopy and high-resolution electrospray ionization mass spectrometry, and the absolute configurations of enantiomers <b>1a</b> and <b>1b</b> were determined by electronic circular dichroism spectroscopy. All the new compounds exhibited antioxidant activities with IC<sub>50</sub> values of 19.45–81.98 μM, as evaluated using free-radical scavenging assays, with the highest activity observed for compound <b>2</b>. In addition, compounds <b>1a</b>, <b>1b</b>, and <b>2</b> exhibited inhibitory activities on intracellular reactive oxygen species generation.
|
|---|