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Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea
S E Huber1, M A Śmiałek2, K Tanzer1
1Institute for Ion Physics and Applied Physics and Center of Molecular Biosciences Innsbruck, Leopold Franzens University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.
The Journal of Chemical Physics
|June 17, 2016
Summary
Dissociative electron attachment to hydroxyurea reveals its potential radiosensitizing capabilities by forming key fragments like NCO(-) and hydroxyl radicals. This study details the fragmentation pathways crucial for understanding its biological effects.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Radiochemistry
Background:
- Hydroxyurea is a drug with known radiosensitizing properties.
- Understanding its fragmentation under electron impact is key to elucidating its biological mechanisms.
- Dissociative electron attachment (DEA) is a sensitive probe of molecular structure and reactivity.
Purpose of the Study:
- To investigate the dissociative electron attachment (DEA) to hydroxyurea in the gas phase.
- To identify major fragmentation pathways and their associated thermodynamic thresholds.
- To evaluate the radiosensitizing potential of hydroxyurea based on its fragmentation patterns.
Main Methods:
- Experiments were conducted using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer.
- Gas-phase hydroxyurea was subjected to electron energies ranging from 0 to 9 eV.
- Mass spectrometry was used to detect and identify fragment ions.
Main Results:
- Dominant dissociation channel observed: formation of NCO(-), water, and amidogen (NH2) radical.
- Secondary dominant channels yield NCNH(-) and NHCONH2 (-), linked to hydroxyl radical formation.
- Other observed ions include NH2(-)/O(-), OH(-), CN(-), HNOH(-), NCONH2 (-), and ONHCONH2 (-).
Conclusions:
- The study identifies key fragmentation channels of hydroxyurea under low-energy electron impact.
- The formation of reactive species like hydroxyl radicals supports hydroxyurea's radiosensitizing capabilities.
- Detailed fragmentation data provides insights into the molecular mechanisms of hydroxyurea's biological effects.
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