Photoexcitation of adenine cation radical [A*+] in the near UV-vis region produces sugar radicals in adenosine and in its nucleotides.

ABSTRACT: In this study, we report the formation of ribose sugar radicals in high yields (85-100%) via photoexcitation of adenine cation radical (A*+) in Ado and its ribonucleotides. Photoexcitation of A*+ at low temperatures in homogeneous aqueous glassy samples of Ado, 2'-AMP, 3'-AMP, and 5'-AMP forms sugar radicals predominantly at C5'- and also at C3'-sites. The C5'* and C3'* sugar radicals were identified employing Ado deuterated at specific carbon sites: C1', C2', and C5'. Phosphate substitution is found to deactivate sugar radical formation at the site of substitution. Thus, in 5'-AMP, C3'* is observed to be the main radical formed via photoexcitation at ca. 143 K, whereas, in 3'-AMP, C5'* is the only species found. These results were supported by results obtained employing 5'-AMP with specif

SUBMITTER: Adhikary A 

PROVIDER: S-EPMC3290692 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature