Isolation and screened neuroprotective active constituents from the roots and rhizomes of Valeriana amurensis.
In previous study, we have screened the effective fraction against Alzheimer's disease (AD-EF) from the extracts of roots and rhizomes of Valeriana amurensis, based on which neuroprotective active constituents from AD-EF were investigated. Six new compounds 1-6, including four iridoids (xiecaoside A-C and xiecaoline A), one pinane-type monoterpeneglucoside (xiecaoside D), and one phenylpropanoid glycoside (xiecaoside E) were isolated together with 11 known compounds 7-17. The structures of 1-6 were elucidated by their spectroscopic data. The protective effects of compounds 1-17 on PC12 cells with neurotoxicity induced by amyloid-beta 1-42 (Aβ(1-42)) was also investigated, respectively. Consequently, compound 6 and lignans 11-17 were responsible for protecting against Aβ-induced toxicity in PC12 cells.