Activity-directed fractionation and purification processes were employed to identify the anti-Alzheimer
active compounds from the root of Angelica sinensis. In this study, the ability of Angelica root to inhibit the
aggregated amyloid b-peptide (agg Ab1-40) induced damage of differentiated PC-12 cells (dPC-12), a wellknown
cell model for Alzheimer disease, was investigated. Air-dried roots of A. sinensis were extracted
with methanol and then separated into ethyl acetate, n-butanol and water layers. Among them, only
the ethyl acetate layer showed strong activity and therefore, subjected to separation and purification
using various chromatographic techniques. Four compounds showing potent activity were identified
by comparing spectral data (UV, NMR, and ESI-MS) with literature values to be Z-ligustilide, 11-angeloylsenkyunolide
F, coniferyl ferulate and ferulic acid. They were found to significantly inhibit Ab1-40 toxicity
on dPC-12 cells at lower concentrations (1–10 lg/ml), but at high concentrations (>50 lg/ml) they
were toxic to the dPC-12 cells, except 11-angeloylsenkyunolide F. DPPH scavenging activity of the
extracts and isolated compounds have also been carried out to find the possible mechanism of the
activity.