Rhee In Kyung, Appels Natalie, Hofte Bertil, Karabatak Bahadir, Erkelens Cornelis, Stark Lucy M, Flippin Lee A, Verpoorte Robert
Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, The Netherlands.
Biol Pharm Bull. 2004 Nov;27(11):1804-9. doi: 10.1248/bpb.27.1804.
In an attempt to isolate the active compound while detecting acetylcholinesterase inhibitory activity, we applied a fluorometric flow assay system to an on-line coupled preparative HPLC. The MeOH extract of Nerine bowdenii showed a strong inhibitory peak in the on-line assay, and the active compound was isolated by CPC and HPLC. It was identified as ungeremine by analysis of its (1)H-NMR, 2D-NMR, and NOESY spectra. The assignment of the active N. bowdenii constituent was also confirmed by co-TLC, co-HPLC, and co-(1)H-NMR experiments using an authentic sample of synthetic ungeremine. The IC(50) value of ungeremine was 0.35 microM, showing stronger activity than galanthamine (2.2 microM).
