Document Detail


Soft ionization mass spectrometry of chromanols produces radical cation molecular ions.
MedLine Citation:
PMID:  15103097     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Several chromanol drug substance candidates exhibit unconventional behavior under the soft ionization conditions of fast atom bombardment and electrospray ionization in the mass spectrometer. Under FAB, these compounds produce radical cation molecular ions rather than protonated molecular ions. Similarly, under acidic mobile phase conditions in an electrospray LC-MS experiment, they produce radial cation molecular ions. Upon changing to a neutral, ammonium acetate-containing mobile phase, the molecular ion species is an ammonium adduct. The two example compounds behave conventionally under negative ion detection, both being free carboxylic acids and forming abundant [M - H](-). Examination of structural analogs indicates that the chromanol, methoxyl and chroman compounds behave this way. Oxidation to a chromanone causes formation of a conventional [M + H](+). Oxidation to a chromene produces even more complex behavior-namely a mixture of [M - H](+), M(+') and [M + H](+). We propose that, for these compounds, elimination of a valence electron to form the radical cation is the more energetically favored reaction than attachment of a proton.
Authors:
Thomas R Sharp
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  European journal of mass spectrometry (Chichester, England)     Volume:  10     ISSN:  1469-0667     ISO Abbreviation:  Eur J Mass Spectrom (Chichester, Eng)     Publication Date:  2004  
Date Detail:
Created Date:  2004-04-22     Completed Date:  2004-07-12     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  101124748     Medline TA:  Eur J Mass Spectrom (Chichester, Eng)     Country:  England    
Other Details:
Languages:  eng     Pagination:  205-12     Citation Subset:  IM    
Affiliation:
Analytical Research & Development Department, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA.
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MeSH Terms
Descriptor/Qualifier:
Antioxidants / chemistry
Cations / chemistry
Chromans / chemistry*
Mass Spectrometry
Molecular Structure
Chemical
Reg. No./Substance:
0/Antioxidants; 0/Cations; 0/Chromans; 950-99-2/2,2,5,7,8-pentamethyl-1-hydroxychroman

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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