Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/344706
Type: Artigo
Title: How does methylation suppress the electron-induced decomposition of 1-methyl-nitroimidazoles?
Author: Kossoski, F.
Varella, M. T. do N.
Abstract: The efficient decomposition of nitroimidazoles (NIs) by low energy electrons is believed to underlie their radiosensitizing properties. Recent dissociative electron attachment (DEA) measurements showed that methylation at the N1 site unexpectedly suppresses the electron-induced reactions in 4(5)-NI. We report theoretical results that provide a clear interpretation of that astounding finding. Around 1.5 eV, DEA reactions into several fragments are initiated by a pi* resonance, not considered in previous studies. The autoionization lifetime of this anion state, which limits the predissociation dynamics, is considerably shorter in the methylated species, thereby suppressing the DEA signals. On the other hand, the lifetime of the pi* resonance located around 3 eV is less affected by methylation, which explains why DEA is still observed at these energies. Our results demonstrate how even a simple methylation can significantly modify the probabilities for DEA reactions, which may be significant for NI-based cancer therapy.
Subject: Elétrons
DNA
Metilação
Electrons
DNA
Methylation
Country: Estados Unidos
Editor: AIP Publishing
Rights: fechado
Identifier DOI: 10.1063/1.5005604
Address: https://aip.scitation.org/doi/10.1063/1.5005604
Date Issue: 2017
Appears in Collections:IFGW - Artigos e Outros Documentos

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