GC-MS of amaryllidaceous galanthamine-type alkaloids.
Galanthamine-type alkaloids produced by plants of the Amaryllidaceae family are potent acetylcholinesterase inhibitors. One of them, galanthamine, has been marketed as a hydrobromide salt for the treatment of Alzheimer's disease. In the present work, gas chromatography with electron impact mass spectrometry (GC-EIMS) fragmentation of 12 reference compounds isolated from various amaryllidaceous plants and identified by spectroscopic methods (1D and 2D nuclear magnetic resonance, circular dichroism, high-resolution MS (HRMS) and EIMS) was studied by tandem mass spectrometry (GC-MS/MS) and accurate mass measurements (GC-HRMS). The studied compounds showed good peak shape and efficient GC separation with a GC-MS fragmentation pattern similar to that obtained by direct insertion probe. With the exception of galanthamine-N-oxide and N-formylnorgalanthamine, the galanthamine-type compounds showed abundant [M](+.) and [M-H](+) ions. A typical fragmentation pattern was also observed, depending on the substituents of the skeleton. Based on the fragmentation pathways of reference compounds, three other galanthamine-type alkaloids, including 3-O-(2'-butenoyl)sanguinine, which possesses a previously unelucidated structure, were identified in Leucojum aestivum ssp. pulchelum, a species endemic to the Balearic islands. GC-MS can be successfully applied to Amaryllidaceae plant samples in the routine screening for potentially new or known bioactive molecules, chemotaxonomy, biodiversity and identification of impurities in pharmaceutical substances.
Departament de Productes Naturals, Biologia Vegetal i Edafologia, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028, Barcelona, Spain. berkov_str@yahoo.com
Strahil
S
Berkov
Francesc
F
Viladomat
Carles
C
Codina
Sergio
S
Suárez
Angel
A
Ravelo
Jaume
J
Bastida
D005702:Galantamine / Q000032:analysis* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007477:Ions / Q000737:chemistry; D019668:Liliaceae / Q000737:chemistry; D008958:Models, Molecular; D053719:Tandem Mass Spectrometry
D007477:Ions; D005702:Galantamine