5hydroxyuracil

5-Hydroxyuracil is a hydroxylated derivative of the nucleobase uracil. In this compound a hydroxy group is attached to the 5-position of the pyrimidine ring, giving the chemical formula C4H4N2O3. It is not part of standard DNA or RNA, but it is studied as an oxidative modification product of uracil.

Occurrence and formation: 5-Hydroxyuracil can arise from oxidative processes in nucleic acids, for example via hydroxyl radical attack on uracil in RNA or DNA, or as a product of enzymatic or chemical hydroxylation in synthetic systems. It has been observed in samples subjected to oxidative stress and may be used as a biomarker of nucleic acid oxidation.

Chemical properties: The extra hydroxyl group influences tautomerism and hydrogen-bonding patterns compared with uracil, and can affect base pairing properties. In solution, several tautomeric forms may be present depending on pH and solvent.

Detection and analysis: 5-Hydroxyuracil is typically detected and quantified by high-performance liquid chromatography coupled with UV or mass spectrometric detection (HPLC-UV, LC-MS). Derivatization and sensitive MS methods enhance detection in biological samples.

Synthesis and applications: It can be synthesized by chemical hydroxylation of uracil under controlled conditions and used as a standard in analytical chemistry and as a model compound in studies of oxidative nucleic acid damage.