Formation of 13C-, 15N-, and 18O-Labeled Guanidinohydantoin from Guanosine Oxidation with Singlet Oxygen. Implications for Structure and Mechanism

Yu Ye, James G. Muller, Wenchen Luo, Charles L. Mayne, Anthony J. Shallop, Roger A. Jones, Cynthia J. Burrows

Research output: Contribution to journalArticlepeer-review

144 Scopus citations

Abstract

Guanosine labeled with 15N at N1, amino, and N7 and 13C at either C2 or C8 was oxidized by Rose Bengal photosensitization (singlet oxygen) in buffered aqueous solution. At pH > 7, spiroiminodihydantoin was the major product, while at pH < 7, guanidinohydantoin (Gh) was the principal product. 15N and 13C NMR studies confirmed that Gh was formed as a mixture of slowly equilibrating diastereomers. Experiments conducted in H218O indicated that Gh and Sp each contained one oxygen atom derived from O2 and one from H2O. Tandem mass spectrometry was used to identify the C4 carbonyl of Gh as the one labeled with 18O, supporting a mechanism involving attack of water at C5 of a dehydro-8-oxoguanosine intermediate.

Original languageEnglish (US)
Pages (from-to)13926-13927
Number of pages2
JournalJournal of the American Chemical Society
Volume125
Issue number46
DOIs
StatePublished - Nov 19 2003

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Biochemistry
  • Catalysis
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Formation of <sup>13</sup>C-, <sup>15</sup>N-, and <sup>18</sup>O-Labeled Guanidinohydantoin from Guanosine Oxidation with Singlet Oxygen. Implications for Structure and Mechanism'. Together they form a unique fingerprint.

Cite this