Chemical Constituents from the Aerial Parts of and Their Protective Activities on Glutamate-Induced HT22 Cell Death.

A new phenolic glucoside, (7,9)-3-hydroxyavenalumic acid-3--[6'--()-caffeoyl]-β-d-glucopyranoside (), and three new acetylated flavone glycosides, acacetin-7--[β-d-glucopyranosyl(1″″→2″)-4‴--acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (), acacetin-7--[6″″--acetylβ-d-glucopyranosyl(1″″→2″)-3‴--acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (), and acacetin-7--[3″″,6″″-di--acetylβ-d-glucopyranosyl(1″″→2″)-4‴--acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (), as well as 34 known compounds (, , , and -) were isolated from the aerial parts of . The chemical structures of the new compounds were determined by spectroscopic/spectrometric data interpretation using NMR and HRESIMS. The neuroprotective effect of the isolated compounds was evaluated by a cell viability assay on HT22 murine hippocampal neuronal cells. Among them, 23 compounds, including new substances and , exhibited neuroprotective effects against glutamate-induced HT22 cell death. In particular, compounds , , , , , , , and presented potent neuroprotective effects with EC values of 1.5-8.3 μM.