Identification of Active Chemical Constituents of Asplenium ruprechtii Sa. Kurata Based on In Vitro Neuroprotective Activity Evaluation

Abstract Mining structural novel and bioactive natural products from traditional Chinese drugs and folk medicines have attracted attention from pharmacologists and pharmaceutical chemists for a long time. In this study, the chemical constituents of Asplenium ruprechtii Sa. Kurata was systematically studied based on the evaluation of neuroprotective activity on hydrogen peroxide (H2O2)-induced damage of SH-SY5Y cell lines. Sixteen chemical monomers (1-16), including two new structures of 9,19-cycloartane-triterpenoid saponins (1,2), were discovered. Their chemical structures were established based on extensive spectroscopic data analysis, including the one- and two-dimensional (1D and 2D) nuclear magnetic resonance (NMR) data and high-resolution electrospray ionization mass spectrometry (HRESIMS). All monomer compounds were docked with an “active pocket” at the N-terminal of the GluN2B protein, where compounds 13-16 were found to possess high binding scores, which warrant further study on the molecular mechanism. Our findings provide insight and research techniques for discovering new drugs based on neuroprotective activity.