Dehydrodimerization of pterostilbene during electrospray ionization mass spectrometry

Handle URI:
http://hdl.handle.net/10754/562732
Title:
Dehydrodimerization of pterostilbene during electrospray ionization mass spectrometry
Authors:
Raji, Misjudeen; Amad, Maan H.; Emwas, Abdul-Hamid M.
Abstract:
RATIONALE Pterostilbene is a member of the hydroxystilbene family of compounds commonly found in plants such as blueberry and grapes. During the analysis of this compound by electrospray ionization mass spectrometry (ESI-MS), an ion was observed that corresponds to the dehydrodimer of pterostilbene in mass-to-charge ratio. Since such unexpected dimerization may lead to decreased monomer signal during quantitative analysis, it was of interest to identify the origin and structure of the observed pterostilbene dimer and examine the experimental conditions that influence its formation. METHODS Liquid Chromatography/Mass Spectrometry (LC/MS), Nuclear Magnetic Resonance (NMR), and High-Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) were used to examine the origin of the dimerization products. The structure of the formed pterostilbene dimer was examined by performing MSn analysis on the dimer ion. Effects of solvent composition, analyte concentration, radical scavenger, and other experimental conditions on the dimerization were also studied. RESULTS LC/MS and NMR analyses clearly showed that the starting solution did not contain the pterostilbene dimer. Solvent type and radical scavenger concentration were found to have pronounced effects on the dimer formation. Particularly, presence of acetonitrile or ammonium acetate had favorable effects on the extent of dimerization during ESI-MS analysis whereas hydroquinone and butylated hydroquinone had negative effects. Dimer formation decreased at high flow rates and when fused-silica capillary was used as the spray needle. CONCLUSIONS The data indicate that this dimerization occurs as a result of solution-phase electrochemical reactions taking place during the electrospray process. A possible structure for this dimer was proposed based on the MSn analysis and was similar to that of the enzymatically derived pterostilbene dehydrodimer already reported in the literature. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.
KAUST Department:
Core Labs; Advanced Nanofabrication, Imaging and Characterization Core Lab
Publisher:
Wiley
Journal:
Rapid Communications in Mass Spectrometry
Issue Date:
30-Apr-2013
DOI:
10.1002/rcm.6571
PubMed ID:
23650039
Type:
Article
ISSN:
09514198
Sponsors:
The authors gratefully acknowledge research support from the Analytical Core Lab and the NMR Core Lab at the King Abdullah University of Science and Technology, Saudi Arabia. The authors also thank Mr. Salim Sioud, Dr. Zeyad Al-Talla, and Dr. Alain Lesimple for assistance and helpful discussions during the experiments.
Appears in Collections:
Articles; Advanced Nanofabrication, Imaging and Characterization Core Lab

Full metadata record

DC FieldValue Language
dc.contributor.authorRaji, Misjudeenen
dc.contributor.authorAmad, Maan H.en
dc.contributor.authorEmwas, Abdul-Hamid M.en
dc.date.accessioned2015-08-03T11:03:38Zen
dc.date.available2015-08-03T11:03:38Zen
dc.date.issued2013-04-30en
dc.identifier.issn09514198en
dc.identifier.pmid23650039en
dc.identifier.doi10.1002/rcm.6571en
dc.identifier.urihttp://hdl.handle.net/10754/562732en
dc.description.abstractRATIONALE Pterostilbene is a member of the hydroxystilbene family of compounds commonly found in plants such as blueberry and grapes. During the analysis of this compound by electrospray ionization mass spectrometry (ESI-MS), an ion was observed that corresponds to the dehydrodimer of pterostilbene in mass-to-charge ratio. Since such unexpected dimerization may lead to decreased monomer signal during quantitative analysis, it was of interest to identify the origin and structure of the observed pterostilbene dimer and examine the experimental conditions that influence its formation. METHODS Liquid Chromatography/Mass Spectrometry (LC/MS), Nuclear Magnetic Resonance (NMR), and High-Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) were used to examine the origin of the dimerization products. The structure of the formed pterostilbene dimer was examined by performing MSn analysis on the dimer ion. Effects of solvent composition, analyte concentration, radical scavenger, and other experimental conditions on the dimerization were also studied. RESULTS LC/MS and NMR analyses clearly showed that the starting solution did not contain the pterostilbene dimer. Solvent type and radical scavenger concentration were found to have pronounced effects on the dimer formation. Particularly, presence of acetonitrile or ammonium acetate had favorable effects on the extent of dimerization during ESI-MS analysis whereas hydroquinone and butylated hydroquinone had negative effects. Dimer formation decreased at high flow rates and when fused-silica capillary was used as the spray needle. CONCLUSIONS The data indicate that this dimerization occurs as a result of solution-phase electrochemical reactions taking place during the electrospray process. A possible structure for this dimer was proposed based on the MSn analysis and was similar to that of the enzymatically derived pterostilbene dehydrodimer already reported in the literature. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.en
dc.description.sponsorshipThe authors gratefully acknowledge research support from the Analytical Core Lab and the NMR Core Lab at the King Abdullah University of Science and Technology, Saudi Arabia. The authors also thank Mr. Salim Sioud, Dr. Zeyad Al-Talla, and Dr. Alain Lesimple for assistance and helpful discussions during the experiments.en
dc.publisherWileyen
dc.titleDehydrodimerization of pterostilbene during electrospray ionization mass spectrometryen
dc.typeArticleen
dc.contributor.departmentCore Labsen
dc.contributor.departmentAdvanced Nanofabrication, Imaging and Characterization Core Laben
dc.identifier.journalRapid Communications in Mass Spectrometryen
kaust.authorRaji, Misjudeenen
kaust.authorAmad, Maan H.en
kaust.authorEmwas, Abdul-Hamid M.en
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