Mass spectrometry of bis-quinolizidine alkaloids: 2- and 17-alkyl-substituted derivatives of sparteine and lupanine

The mass spectral fragmentations of 2‐methylsparteine (1), 2,17‐dimethylsparteine (2), 2‐methyl‐17‐isopropylsparteine (3), 2‐methyl‐17‐oxosparteine (4), 2‐oxo‐17‐methylsparteine (17‐methyllupanine) (5) and 2‐oxo‐17‐isopropylsparteine (17‐isopropyllupanine) (6) were investigated. Fragmentation pathways, whose identification was assisted by accurate mass measurements and a correlation between the abundances of the M+· and selected fragment ions of the investigated compounds, are discussed. The data obtained create the basis for distinguishing the structural isomers and metamers. Copyright © 2000 John Wiley & Sons, Ltd.