title: Isolation of the acetylcholinesterase inhibitor ungeremine from Nerine bowdenii by preparative HPLC coupled on-line to a flow assay system.
abstract: 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).
authors.affiliation: Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, The Netherlands.
authors.forename: In Kyung
authors.initials: IK
authors.lastname: Rhee
authors.forename: Natalie
authors.initials: N
authors.lastname: Appels
authors.forename: Bertil
authors.initials: B
authors.lastname: Hofte
authors.forename: Bahadir
authors.initials: B
authors.lastname: Karabatak
authors.forename: Cornelis
authors.initials: C
authors.lastname: Erkelens
authors.forename: Lucy M
authors.initials: LM
authors.lastname: Stark
authors.forename: Lee A
authors.initials: LA
authors.lastname: Flippin
authors.forename: Robert
authors.initials: R
authors.lastname: Verpoorte
mesh_terms: D047151:Amaryllidaceae Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005470:Fluorometry; D007212:Indolizines / Q000737:chemistry / Q000302:isolation & purification*; D019668:Liliaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D035281:Plant Tubers / Q000737:chemistry
chemical_list: D047151:Amaryllidaceae Alkaloids; D002800:Cholinesterase Inhibitors; D007212:Indolizines; C016175:ungeremine