Narcissus and Daffodil

Acetylcholinesterase inhibitors 375
Figure 15.4 The spectra and the chromatograms obtained after injection of the fraction
from narcissus ‘Sir Winston Churchill’ extract into the on-line HPLC-
UV-MS-bioactivity detection system. Left: ESI-MS. Right: Chromatograms
from the biochemical detection set at 405 nm (upper line) and from the
UV set at 215 nm (lower line). The delay time of the peaks between the
biochemical detection and the UV was 2.3 ± 0.1 min and the delay time of
the peaks between the biochemical detector and the MS was 2.1 ± 0.1 min.
O
O
HO
H
16
OCH3
OH
3
H
N
HCO
3
ungiminorine galanthamine
O
microplate assay. The inhibitory activity was found only in the compound with
molecular weight of 265. This active compound was identified as an alkaloid,
ungiminorine (Figure 15.5). This compound was first isolated by Normatov et al.
(1965). The IC 50 value of ungiminorine was 86 ± 7 µM while that of galanthamine
was 0.98 ± 0.07 µM. Although this compound shows much lower AChE inhibitory
activity compared with that of galanthamine, it clearly demonstrates the usefulness
of the on-line HPLC-UV-MS-biochemical detection for the search of new leads
from natural products.
N
CH3
OH
Figure 15.5 Structure of ungiminorine and galanthamine.