5-Selenocyanatouracil: A Potential Hypoxic Radiosensitizer. Electron Attachment Induced Formation of Selenium Centered Radical

• DOI: 10.1021/acs.jpcb.7b03633
• Publication Date: 2017-06-02T16:14:34Z
• Authors: Marta Sosnowska; Samanta Makurat; Magdalena Zdrowowicz; Janusz Rak
• Keywords: Radiosensitizer

The propensity of 5-selenocyanatouracil (SeCNU) to decomposition induced by attachment electron was scrutinized with the G3B3 composite quantum-chemical method and radiolytic studies. Favorable thermodynamic (Gibbs free reaction energy -13.65 kcal/mol) kinetic activation 1.22 characteristics revealed profile suggest SeCNU be sensitive attachment. title compound synthesized in between uracil selenocyanogen chloride acetic acid. Then, an aqueous deoxygenated solution HPLC purified containing tert-butanol as a hydroxyl radical scavenger irradiated X-rays. radio-degradation results two major products: U-Se-Se-U dimer adduct ●OtBu U-Se● radical, U-Se-OtBu. effects radiolysis well calculations point primary product dissociative SeCNU. MTT test shows that is nontoxic vitro concentrations equal or lower than 10-6 M. Ionizing radiation will probably induce cytotoxic intra- interstrand DNA cross-links protein-DNA genomic labeled