Chemical Constituents of the Egg Cases of (Mantidis ootheca) with Intracellular Reactive Oxygen Species Scavenging Activity.

As a traditional medicine with potential antioxidant effects, egg cases (Mantidis ootheca) are a potential source of new bioactive substances. Herein, three new -acetyldopamine derivatives, namely, (+)-tenoderin A (), (-)-tenoderin A (), and tenoderin B (), along with thirteen known compounds (-), were isolated from a 70% EtOH extract of . egg cases. Compound was isolated as a racemic mixture, and two enantiomers ( and ) 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 and were determined by electronic circular dichroism spectroscopy. All the new compounds exhibited antioxidant activities with IC values of 19.45-81.98 μM, as evaluated using free-radical scavenging assays, with the highest activity observed for compound . In addition, compounds , , and exhibited inhibitory activities on intracellular reactive oxygen species generation.