Nucleoside Cation Radicals: Generation, Radical-Induced Hydrogen Atom Migrations, and Ribose Ring Cleavage in the Gas Phase

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F24%3A00587176" target="_blank" >RIV/61388963:_____/24:00587176 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1021/jasms.4c00198" target="_blank" >https://doi.org/10.1021/jasms.4c00198</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/jasms.4c00198" target="_blank" >10.1021/jasms.4c00198</a>

Result language

angličtina

Original language name

Nucleoside Cation Radicals: Generation, Radical-Induced Hydrogen Atom Migrations, and Ribose Ring Cleavage in the Gas Phase

Original language description

Nucleoside ions that were furnished on ribose with a 2 '-O-acetyl radical group were generated in the gas phase by multistep collision-induced dissociation of precursor ions tagged with radical initiator groups, and their chemistry was investigated in the gas phase. 2 '-O-Acetyladenosine cation radicals were found to undergo hydrogen transfer to the acetoxyl radical from the ribose ring positions that were elucidated using specific deuterium labeling of 1 '-H, 2 '-H, and 4 '-H and in the N-H and O-H exchangeable positions, favoring 4 '-H transfer. Ion structures and transition-state energies were calculated by a combination of Born-Oppenheimer molecular dynamics and density functional theory and used to obtain unimolecular rate constants for competitive hydrogen transfer and loss of the acetoxyl radical. Migrations to the acetoxyl radical of ribose hydrogens 1 '-H, 2 '-H, 3 '-H, and 4 '-H were all exothermic, but product formation was kinetically controlled. Both Rice-Ramsperger-Kassel-Marcus (RRKM) and transition-state theory (TST) calculations indicated preferential migration of 4 '-H in a qualitative agreement with the deuterium labeling results. The hydrogen migrations displayed substantial isotope effects that along with quantum tunneling affected the relative rate constants and reaction branching ratios. UV-vis action spectroscopy indicated that the cation radicals from 2 '-O-acetyladenosine consisted of a mixture of isomers. Radical-driven dissociations were also observed for protonated guanosine, cytosine, and thymidine conjugates. However, for those nucleoside ions and cation radicals, the dissociations were dominated by the loss of the nucleobase or formation of protonated nucleobase ions.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10406 - Analytical chemistry

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

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of the American Society for Mass Spectrometry

ISSN

1044-0305

e-ISSN

1879-1123

Volume of the periodical

35

Issue of the periodical within the volume

7

Country of publishing house

US - UNITED STATES

Number of pages

15

Pages from-to

1594-1608

UT code for WoS article

001242769700001

EID of the result in the Scopus database

2-s2.0-85195782377