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Updated: May 19, 2026

Uracil-DNA Glycosylase Assay by Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry Analysis

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Published on: April 22, 2022

Fragmentation pathways in the uracil radical cation.

Congyi Zhou¹, Spiridoula Matsika, Marija Kotur

¹Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA.

The Journal of Physical Chemistry. A

|August 28, 2012

Summary

Uracil radical cation fragmentation pathways were studied. Sequential fragmentation, especially after forming the m/z 69 ion, is the primary route for smaller fragment production.

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Area of Science:

Physical Chemistry
Computational Chemistry
Chemical Physics

Background:

Uracil is a fundamental component of nucleic acids.
Understanding radical cation fragmentation is crucial for mass spectrometry and radiation chemistry.
Previous studies have identified key fragments but lacked detailed mechanistic insights.

Purpose of the Study:

To elucidate fragmentation pathways of the uracil radical cation.
To determine the energetic barriers for dissociation into major fragments (m/z 69, 28, 41, 42).
To differentiate between direct and sequential fragmentation mechanisms.

Main Methods:

Ab initio electronic structure calculations were employed.
Focus on the ground ionic potential energy surface.
Analysis of dissociation barriers and reaction mechanisms.

Main Results:

Energetic barriers for dissociation to primary fragments were calculated.
Direct fragmentation pathways were investigated.
Sequential fragmentation, particularly via the m/z 69 fragment, was identified as dominant for smaller fragment formation.

Conclusions:

Sequential fragmentation is the predominant mechanism for producing smaller fragments from uracil radical cations.
The m/z 69 fragment plays a key role in subsequent dissociation events.
Computational insights provide a foundation for interpreting experimental dissociative ionization data.