Competitive Radical Migrations and Ribose Ring Cleavage in Adenosine and 2′-Deoxyadenosine Cation Radicals
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F24%3A00583414" target="_blank" >RIV/61388963:_____/24:00583414 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1021/acs.jpca.3c07906" target="_blank" >https://doi.org/10.1021/acs.jpca.3c07906</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpca.3c07906" target="_blank" >10.1021/acs.jpca.3c07906</a>
Alternative languages
Result language
angličtina
Original language name
Competitive Radical Migrations and Ribose Ring Cleavage in Adenosine and 2′-Deoxyadenosine Cation Radicals
Original language description
We report a combined experimental and computational study of adenosine cation radicals that were protonated at adenine and furnished with a radical handle in the form of an acetoxyl radical, (CH2COO)-C-center dot, that was attached to ribose 5'-O. Radicals were generated by collision-induced dissociation (CID) and characterized by tandem mass spectrometry and UV-vis photodissociation action spectroscopy. The acetoxyl radical was used to probe the kinetics of intramolecular hydrogen transfer from the ribose ring positions that were specifically labeled with deuterium at C1', C2', C3', C4', C5', and in the exchangeable hydroxyl groups. Hydrogen transfer was found to chiefly involve 3'-H with minor contributions by 5'-H and 2'-H, while 4'-H was nonreactive. The hydrogen transfer rates were affected by deuterium isotope effects. Hydrogen transfer triggered ribose ring cleavage by consecutive dissociations of the C4'-O and C1'-C2' bonds, resulting in expulsion of a C6H9O4 radical and forming a 9-formyladenine ion. Rice-Ramsperger-Kassel-Marcus (RRKM) and transition-state theory (TST) calculations of unimolecular constants were carried out using the effective CCSD(T)/6-311++G(3d,2p) and M06-2X/aug-cc-pVTZ potential energy surfaces for major isomerizations and dissociations. The kinetic analysis showed that hydrogen transfer to the acetoxyl radical was the rate-determining step, whereas the following ring-opening reactions in ribose radicals were fast. Using DFT-computed energies, a comparison was made between the thermochemistry of radical reactions in adenosine and 2'-deoxyadenosine cation radicals. The 2'-deoxyribose ring showed lower TS energies for both the rate-determining 3'-H transfer and ring cleavage reactions.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10406 - Analytical chemistry
Result continuities
Project
<a href="/en/project/LTAUSA19094" target="_blank" >LTAUSA19094: Electron and proton transfer in ionized DNA fragments</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2024
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Physical Chemistry A
ISSN
1089-5639
e-ISSN
1520-5215
Volume of the periodical
128
Issue of the periodical within the volume
6
Country of publishing house
US - UNITED STATES
Number of pages
15
Pages from-to
1109-1123
UT code for WoS article
001163382300001
EID of the result in the Scopus database
2-s2.0-85184821794