Billinghurst Brant E, Loppnow Glen R
Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
J Phys Chem A. 2006 Feb 23;110(7):2353-9. doi: 10.1021/jp0561571.
Cytosine, a nucleobase found in both DNA and RNA, is known to form photoproducts upon UV irradiation, damaging the nucleic acids and leading to cancer and other diseases. To determine the molecular mechanism by which these photoproducts occur, we have measured the resonance Raman spectra of cytosine at wavelengths throughout its 267 nm absorption band. Self-consistent analysis of the resulting resonance Raman excitation profiles and absorption spectrum using a time-dependent wave packet formalism yields both the excited-state structural changes and electronic parameters. From this analysis, we have been able to determine that, at most, 31% of the reorganization energy upon excitation is directed along photochemically relevant modes.
胞嘧啶是一种存在于DNA和RNA中的核碱基，已知在紫外线照射下会形成光产物，破坏核酸并导致癌症和其他疾病。为了确定这些光产物产生的分子机制，我们测量了胞嘧啶在其267nm吸收带整个波长范围内的共振拉曼光谱。使用含时波包形式对所得的共振拉曼激发轮廓和吸收光谱进行自洽分析，得到了激发态结构变化和电子参数。通过该分析，我们能够确定，激发时最多31%的重组能沿着光化学相关模式分布。
