Analysis of Amaryllidaceae alkaloids from Crinum by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

A high-performance liquid chromatography/electrospray ionization multi-stage tandem mass spectrometry (HPLC/ESI-MSn) method was developed to analyze two structurally related groups of Amaryllidaceae alkaloids (AmAs), crinane- and tazettine-type alkaloids, in the species Crinum latifolium and C. asiaticum, as well as different organs of C. latifolium. In ESI-MSn spectra of the two types of alkaloids, characteristic fragmentation reactions were observed that allowed us to determine and differentiate them. Based on the fragmentation rules of reference standards, crinane-type alkaloids displayed concurrent neutral loss of C2H5N (43 u) and C2H6N (44 u) as well as characteristic ions of m/z 213 and 211, whereas tazettine-type alkaloids exhibited neutral loss of C3H7N (57 u) [or C2H5N (43 U), C3H7NO (73 u)] from the [M+H](+) and [M+H-H2O](+) ions. These were supported by quadrupole time-of-flight (Q-Tof)-MS/MS analysis. The chemical complexity of the mixture was resolved by profiling. The compositions of the main crinane- and tazettine-type alkaloids in the above-mentioned species and organs were also compared. Overall, 28 AmAs comprising 14 crinane-type and 14 tazettine-type alkaloids were identified and studied by MS. Among them, 14 AmAs were tentatively characterized from the two species for the first time. This method allowed a rapid analysis of alkaloid distribution and composition of Crinum species, and may also be used for quality control and screening of extracts designated for pharmaceutical application. Copyright (C) 2009 John Wiley & Sons, Ltd.