New 2,3‐Methylenedioxy‐naphthalene Derivatives With Neuroprotective Activity From the Roots of Ephedra sinica Stapf

ABSTRACT Four new 2,3‐methylenedioxy‐naphthalene derivatives, named ephedplics A–D (1–4), were isolated from the roots of Ephedra sinica Stapf. The structures of compounds 1 – 4 were elucidated through comprehensive analyses of ultraviolet, infrared, high‐resolution electrospray ionization mass spectrometry, and one‐/two‐dimensional nuclear magnetic resonance data. Ephedplics A–D represent newly identified natural derivatives featuring a 2,3‐methylenedioxy‐naphthalene scaffold. Furthermore, the isolated compounds were evaluated for their protective effects against corticosterone‐induced injury in rat pheochromocytoma (PC‐12) cells in vitro. Compounds 2 – 4 exhibited significant neuroprotective activity, potentially by mitigating the decline in mitochondrial membrane potential, reducing Ca 2+ influx into PC‐12 cells, and significantly increasing cell viability while decreasing the apoptosis rate. The results indicate that compounds 1 – 4 are novel and that compounds 2 – 4 may show neuroprotective effects.