A new phenanthrene dimer, namely dendropalpebrone (1), was isolated from the whole plant of Dendrobium palpebre, along with nine known compounds (2-10). All of the isolates were evaluated for their hydroxyl radical scavenging effects using a deoxyribose assay. Dendroflorin (10) showed an appreciable activity, and therefore was selected for further studied in RAW264.7 cells. Compound 10 significantly decreased ROS in H2O2-stimulated RAW264.7 cells in a dose-dependent manner, and improved activity of SOD, GPx, and CAT enzymes.
Keywords: Orchidaceae; antioxidant; dendroflorin; phenanthrene dimer.