Differentiation between 3,4- and 4,15-Epoxyeudesmanolides by Electrospray Ionization Tandem Mass Spectrometry.
Herbert Júnior DiasRicardo StefaniJosé Carlos TomazRicardo VessecchiAntônio Eduardo Miller CrottiPublished in: Journal of analytical methods in chemistry (2017)
We investigated the fragmentation of the eudesmanolide-type sesquiterpene lactones 1α-(4-hydroxymethacryloyloxy)-3α,4α-epoxy-8α-hydroxyeudesm-11(13)-6α,12-olide (1) and 1α-(2,3-epoxyangeloyloxy)-4α,15-epoxy-8α-hydroxyeudesm-11(13)-6α,12-olide (2) by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The elimination of the different ester substituent at C(1) directly from protonated 1 and 2 (A) led to the formation of two regioisomer product ions B (A - RCO2H). Further fragmentation of B resulted from consecutive eliminations of H2O and CO molecules. However, we identified four product ions that allowed for the differentiation between 3,4- and 4,15-epoxyeudesmanolides. The formation of these diagnostic ions was associated with the C(3)-O bond of compound 1, which propitiates the participation of the lone pair of the oxygen epoxide in the formation of B through a Grob-Wharton-type fragmentation, then resulting in an alternative fragmentation pathway. These data can be useful for the fast differentiation between epoxyeudesmanolide regioisomers directly from Dimerostemma extracts by liquid chromatography-tandem mass spectrometry (LC-MS/MS), as an alternative to NMR, or even for quantitation studies of these compounds using multiple reaction monitoring (MRM) scan.
Keyphrases
- tandem mass spectrometry
- liquid chromatography tandem mass spectrometry
- simultaneous determination
- ultra high performance liquid chromatography
- ms ms
- solid phase extraction
- high performance liquid chromatography
- liquid chromatography
- gas chromatography
- high resolution
- quantum dots
- mass spectrometry
- high resolution mass spectrometry
- computed tomography
- aqueous solution
- water soluble
- electronic health record
- machine learning
- big data