Premium
Mass spectrometry of 3,5‐ and 4,5‐dicaffeoylquinic acids and selected derivatives
Author(s) -
Miketova Petra,
Schram Karl H.,
Whitney Jeffery,
Kearns Edward H.,
Timmermann Barbara N.
Publication year - 1999
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/(sici)1096-9888(199912)34:12<1240::aid-jms896>3.0.co;2-b
Subject(s) - chemistry , electron ionization , fragmentation (computing) , electrospray ionization , mass spectrometry , caffeic acid , mass spectrum , trimethylsilyl , ion , polyatomic ion , fast atom bombardment , quinic acid , structural isomer , medicinal chemistry , stereochemistry , ionization , computational chemistry , analytical chemistry (journal) , organic chemistry , chromatography , antioxidant , computer science , operating system
The mass spectral properties of 3,5‐ and 4,5‐dicaffeoylquinic acids (DCQAs) and selected derivatives were examined using electron ionization (EI), fast atom bombardment (FAB) and electrospray ionization (ESI). EI analysis of the trimethylsilyl derivatives provides molecular mass ( M r ) information, but the spectrum is dominated by fragment ions of the caffeic acid group; isomers cannot be differentiated using EI. FAB analysis, in both the positive and negative ion detection modes, provides M r information on the free compounds, but little fragmentation is observed using normal scan conditions. The FAB mass‐analyzed ion kinetic energy spectroscopic analysis of the free compounds does, however, permit differentiation of the isomers, with 3,5‐DCQA showing selective loss of water, a process not observed with the 4,5‐isomer. Both EI and FAB provide M r and some structural information when applied to the peracetate derivatives of the DCQAs. ESI of the DCQAs provides considerably more structural information, especially in the negative ion detection mode, and is the recommended method of analysis of the quinic acid esters. M r information, identity of the ester groups and differentiation of isomers are possible using ESI. Copyright © 1999 John Wiley & Sons, Ltd.