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4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution

Abstract

In the pulse radiolysis of 2'-deoxycytidine (dCyd) in N{sub 2}O-saturated solutions containing 0.5M tertiary butanol to completely scavenge the water radicals, a short-lived intermediate ({lambda}max=287nm) is observed by UV spectroscopy which is attributed to dCydH{sup +}, generated in the reaction of dCyd with H{sup +} formed during the pulse. By reacting with OH{sup -}, which is formed in the pulse in amounts matching that of H{sup +}, this intermediate disappears in the {mu}s time range without a change of the spectrum. Similarly, cytosine (Cyt) gives rise to CytH{sup +} which, in contrast, in part transforms into another species ({lambda}max=286nm) which can be assigned to isocytosine 1, 4-amino-3H-pyrimidin-2-one, a tautomer of Cyt which is formed by two routes (i) deprotonation of CytH{sup +} at N(1) by OH{sup -} and (ii) deprotonation of Cyt and reprotonation of the Cyt anion by water at N(3). Compared to Cyt, 1 is richer in Gibbs' free enthalpy by 14kJmol{sup -1}. Its presence in low equilibrium concentrations has also been observed by conventional UV spectroscopy, making use of the increase of its equilibrium concentration with increasing temperature. From these data, an absorption coefficient of 3.3x10{sup 4}dm{sup 3}mol{sup -1}cm{sup -1} at 286nm has been calculated. Supporting quantum  More>>
Authors:
Nien Schuchmann, Man; [1]  Naumov, Sergej; [2]  Schuchmann, Heinz-Peter; [1]  Sonntag, Justus von; [3]  Sonntag, Clemens von; [1]  Leibniz-Institut fuer Oberflaechenmodifizierung - IOM, Permoserstr. 15, D-04303 Leipzig (Germany)]. E-mail: Clemens@vonSonntag.de
  1. Max-Planck-Institut fuer Bioanorganische Chemie (formerly: Strahlenchemie), Stiftstr. 34-36, P.O. Box 101365, D-45413 Muelheim an der Ruhr (Germany)
  2. Leibniz-Institut fuer Oberflaechenmodifizierung -IOM, Permoserstr. 15, D-04303 Leipzig (Germany)
  3. Leibniz-Institut fuer Oberflaechenmodifizierung - IOM, Permoserstr. 15, D-04303 Leipzig (Germany)
Publication Date:
Feb 01, 2005
Product Type:
Journal Article
Resource Relation:
Journal Name: Radiation Physics and Chemistry (1993); Journal Volume: 72; Journal Issue: 2-3; Other Information: DOI: 10.1016/j.radphyschem.2003.12.058; PII: S0969-806X(04)00503-1; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); PBD: Feb 2005
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; AQUEOUS SOLUTIONS; BUTANOLS; CYTOSINE; DEOXYCYTIDINE; FREE ENTHALPY; HYDROGEN IONS 1 PLUS; HYDROXIDES; NITROUS OXIDE; PULSES; RADICALS; RADIOLYSIS; SPECTRA; SPECTROSCOPY; ULTRAVIOLET RADIATION; WATER
OSTI ID:
20620247
Country of Origin:
United Kingdom
Language:
English
Other Identifying Numbers:
Journal ID: ISSN 0969-806X; RPCHDM; TRN: GB05R3069063897
Submitting Site:
GBN
Size:
page(s) 243-250
Announcement Date:
Aug 28, 2005

Citation Formats

Nien Schuchmann, Man, Naumov, Sergej, Schuchmann, Heinz-Peter, Sonntag, Justus von, Sonntag, Clemens von, and Leibniz-Institut fuer Oberflaechenmodifizierung - IOM, Permoserstr. 15, D-04303 Leipzig (Germany)]. E-mail: Clemens@vonSonntag.de. 4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution. United Kingdom: N. p., 2005. Web. doi:10.1016/j.radphyschem.2003.12.058.
Nien Schuchmann, Man, Naumov, Sergej, Schuchmann, Heinz-Peter, Sonntag, Justus von, Sonntag, Clemens von, & Leibniz-Institut fuer Oberflaechenmodifizierung - IOM, Permoserstr. 15, D-04303 Leipzig (Germany)]. E-mail: Clemens@vonSonntag.de. 4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution. United Kingdom. https://doi.org/10.1016/j.radphyschem.2003.12.058
Nien Schuchmann, Man, Naumov, Sergej, Schuchmann, Heinz-Peter, Sonntag, Justus von, Sonntag, Clemens von, and Leibniz-Institut fuer Oberflaechenmodifizierung - IOM, Permoserstr. 15, D-04303 Leipzig (Germany)]. E-mail: Clemens@vonSonntag.de. 2005. "4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution." United Kingdom. https://doi.org/10.1016/j.radphyschem.2003.12.058.
@misc{etde_20620247,
title = {4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution}
author = {Nien Schuchmann, Man, Naumov, Sergej, Schuchmann, Heinz-Peter, Sonntag, Justus von, Sonntag, Clemens von, and Leibniz-Institut fuer Oberflaechenmodifizierung - IOM, Permoserstr. 15, D-04303 Leipzig (Germany)]. E-mail: Clemens@vonSonntag.de}
abstractNote = {In the pulse radiolysis of 2'-deoxycytidine (dCyd) in N{sub 2}O-saturated solutions containing 0.5M tertiary butanol to completely scavenge the water radicals, a short-lived intermediate ({lambda}max=287nm) is observed by UV spectroscopy which is attributed to dCydH{sup +}, generated in the reaction of dCyd with H{sup +} formed during the pulse. By reacting with OH{sup -}, which is formed in the pulse in amounts matching that of H{sup +}, this intermediate disappears in the {mu}s time range without a change of the spectrum. Similarly, cytosine (Cyt) gives rise to CytH{sup +} which, in contrast, in part transforms into another species ({lambda}max=286nm) which can be assigned to isocytosine 1, 4-amino-3H-pyrimidin-2-one, a tautomer of Cyt which is formed by two routes (i) deprotonation of CytH{sup +} at N(1) by OH{sup -} and (ii) deprotonation of Cyt and reprotonation of the Cyt anion by water at N(3). Compared to Cyt, 1 is richer in Gibbs' free enthalpy by 14kJmol{sup -1}. Its presence in low equilibrium concentrations has also been observed by conventional UV spectroscopy, making use of the increase of its equilibrium concentration with increasing temperature. From these data, an absorption coefficient of 3.3x10{sup 4}dm{sup 3}mol{sup -1}cm{sup -1} at 286nm has been calculated. Supporting quantum chemical calculations are also reported.}
doi = {10.1016/j.radphyschem.2003.12.058}
journal = []
issue = {2-3}
volume = {72}
journal type = {AC}
place = {United Kingdom}
year = {2005}
month = {Feb}
}