Chemical constituents of Wikstroemia alternifolia and their neuroprotective activities.

Phytochemical investigation on the plant of Wikstroemia alternifolia led to the isolation of 26 compounds including two new ones, wikstralternifols A and B (1 and 7). Their structures including the absolute configuration were elucidated by spectroscopic data together with analysis of experimental and calculated ECD data. All compounds were isolated from this plant for the first time, and their main structural types were lignans, sesquiterpenoids, and flavonoids. In the sodium nitroprusside-induced rat pheochromocytoma PC-12 cell model, the neuroprotective activities of the selected sesquiterpenoids (1 and 4) and lignans (7 - 14) were screened at the concentration of 10 µM, and 7 - 14 displayed better activities than the positive control edaravone.