Electrospray ionization tandem mass spectrometric study of the aconitines in the roots of aconite.
Fragmentation pathways of aconitine-type alkaloids were investigated by electrospray ionization/ion trap multistage tandem mass spectrometry. Low-energy collision-induced dissociation of protonated aconitines follows a dominant first step, the elimination of the C(8)-substituent as acetic acid or fatty acid in MS(2) spectra. Successive losses of 1-4 CH(3)OH molecules, 1-3 H(2)O, CO, benzoic acid, and CH(3) or C(2)H(5) (N-substituents) are all fragmentation pathways observed in MS(3) and MS(4) spectra. By applying knowledge of these fragmentation pathways to the aconitines in the ethanolic extract of aconite roots, all the known aconitines were detected and also 23 unknown aconitine-type alkaloids, in which the lipo-alkaloids containing residues of 15C, 17C and 19C saturated or unsaturated fatty acids were characterized. These odd-carbon-number fatty acid substituents have not been reported previously.
Wang
Yong
Y
The New Drug Laboratory of the Changchun Institute of Applied Chemistry, Changchun 130022, P. R. China.
Liu
Zhiqiang
Z
Song
Fengrui
F
Liu
Shuying
S
D000157:Aconitine / Q000032:analysis* / Q000737:chemistry; D031841:Aconitum / Q000737:chemistry*; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000157:Aconitine