Phenolic Glycosides From Ficus erecta and Their Anti-Inflammatory and Neuroprotective Activities

Five undescribed phenolic glycosides, ficuserectosides A-E (1-5), and three previously reported congeners (6-8) were obtained from the whole plants of Ficus erecta. Their structures were determined by comprehensive analysis of 1D and 2D NMR and HRESIMS data. The identities and configurations of the monosaccharide units were established after hydrolysis and subsequent chiral derivatization followed by HPLC analysis. Notably, ficuserectoside E (5) was established as a Z-configured prenylated coumarin glucoside, enabling revision of a previously misassigned related structure. All of the isolates were evaluated in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and in a 6-hydroxydopamine (6-OHDA)-induced PC12 cell injury model. None of the compounds significantly inhibited nitric oxide (NO) production at 25 or 50 µM. However, compounds 5 and 8 dose-dependently (12.5-50 µM) improved PC12 cells survival, as evidenced by reduced intracellular reactive oxygen species (ROS) accumulation and increased cellular glutathione (GSH) levels. The present findings not only broaden the structural spectrum of Ficus erecta phenolic glycosides but also highlight selected glycosylated phenolics as promising leads for antioxidant-based neuroprotective candidates.