New Iridoid Derivatives from the Fruits of Cornus officinalis and Their Neuroprotective Activities

Three previously undescribed iridoids, cornusfurals A⁻C, were isolated from the ethanolic extracts of fruits of Cornus officinalis. Their structures were elucidated by spectroscopic methods, including one-dimensional and two-dimensional nuclear magnetic resonance, ultraviolet spectroscopy, infrared spectroscopy, and mass spectrometry. The neuroprotective activity was evaluated by measuring corticosterone-induced damage in PC12 cells. The results showed that cornusfural B decreased corticosterone-induced PC12 cell damage compared with that in model cells.