Fragmentation Studies of Monensin A and B in Negative Electrospray and Nanospray Tandem Mass Spectrometry

2007 ◽  
Vol 13 (3) ◽  
pp. 191-198 ◽  
Author(s):  
José N. Sousa-Junior ◽  
Paul J. Gates ◽  
Norberto P. Lopes
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Major Product ◽  
Negative Ion ◽  
Tandem Mass ◽  
Fragmentation Chemistry ◽  
Product Ions ◽  
Low Mass ◽  
Monensin A ◽  
Negative Ion Mode

This paper reports the first comparative study of the gas-phase fragmentation chemistry of monensin in negative ion mode electrospray and nanoelectrospray tandem mass spectrometry. The fragmentation was observed to occur at lower energies in nanoelectrospray than electrospray. The major product ions are proposed to be formed via an initial neutral elimination of methanol followed be subsequent fragmentation. The low-mass product ions were observed at the same m/z for both monensin A and B.

scholarly journals Characterisation of Flavonoid Aglycones by Negative Ion Chip-Based Nanospray Tandem Mass Spectrometry

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Paul J. Gates ◽  
Norberto P. Lopes
Keyword(s):  
Mass Spectrometry ◽  
Reliable Method ◽  
Biological Activities ◽  
Distinct Pattern ◽  
Negative Ion ◽  
Tandem Mass ◽  
Flavonoid Aglycones ◽  
Product Ions ◽  
Low Mass ◽  
Tea Extract

Flavonoids are one of the most important classes of natural products having a wide variety of biological activities. There is wide interest in a range of medical and dietary applications, and having a rapid, reliable method for structural elucidation is essential. In this study a range of flavonoid standards are investigated by chip-based negative ion nanospray mass spectrometry. It was found that the different classes of flavonoid studied have a combination of distinct neutral losses from the precursor ion [M-H]−along with characteristic low-mass ions. By looking only for this distinct pattern of product ions, it is possible to determine the class of flavonoid directly. This methodology is tested here by the analysis of a green tea extract, where the expected flavonoids were readily identified, along with quercetin, which is shown to be present at only about 2% of the most intense ion in the spectrum.

Sign in / Sign up

Export Citation Format

Share Document