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Differentiation of three pairs of aconite alkaloid isomers from Aconitum nagarum var. lasiandrum by electrospray ionization tandem mass spectrometry
Author(s) -
Li Rui,
Wu Zhijun,
Zhang Fan,
Ding Lisheng
Publication year - 2005
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2283
Subject(s) - chemistry , aconitum , aconitine , tandem mass spectrometry , electrospray ionization , mass spectrometry , fragmentation (computing) , alkaloid , structural isomer , substituent , stereochemistry , medicinal chemistry , chromatography , computer science , operating system
Abstract Three pairs of isomers of aconite alkaloids from Aconitum nagarum var. lasiandrum have been investigated by electrospray ionization mass spectrometry (ESI‐MS) and tandem mass spectrometry (MS/MS) employing ion‐trap and quadrupole time‐of‐flight mass spectrometers in positive mode. Based on the differences of their fragmentation pathways and special fragment ions, three pairs of isomers of aconite alkaloids were differentiated. In addition, fragmentation laws of some veatchines and the discrepancy of fragmentation mechanisms between veatchine‐type and aconitine‐type alkaloid were also concluded. In the case of veatchines, a radical would be formed by homolysis of C18C4 or C18H bonds, followed by elimination of a series of C 2 H 2 and C 2 H 4 . Moreover, the retro‐Diels‐Alder (RDA) reaction occurred in the E‐ring and double‐electron transfer triggered by the positive charge on C1 led to the formation of diagnostic ions at m/z 216. With regard to aconitine‐type alkaloids, the N‐substituent is not eliminated easily. Although there is no carbonyl group on some aconitine‐type alkaloids, with hydroxyl and methoxyl on C15 and C16 respectively, CO was readily eliminated through tautomerization. Copyright © 2005 John Wiley & Sons, Ltd.