Solvent type influence on thymidine UV-sensitivity

[摘要] Thymine is the most sensitive DNA nucleobase to UV-irradiation. In the thymidine solution the photoreactions probability is in dependence on the solvent properties which determine stacking-mediated thymidine association and lifetime of excited states. In this work we investigated the degree of UV-irradiation induced thymidine damages in water, salt (NaCl) and ethanol solvents using UV absorption and circular dichroism (CD) spectrometry, and MS ESI method. In the explored systems thymidine association degree rose in the following solvent order: 1 M NaCl, water, ethanol. UV-absorbance and CD intensity fell in the greater extent in the ethanol and water-salt solutions than in water. So the experiment showed that the association degree of thymidine in the solution does not play a main role in its photosensitivity.

[发布机构] Laboratory of Molecular Biophysics, Department of Molecular Biophysics, St. Petersburg State University, Ulyanovskaya st. 3, Petergof, St.Petersburg, Russia^1

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Circular dichroism spectrometries;Photoreactions;Solvent properties;UV absorbance;UV absorption;UV irradiation;UV sensitivity;Water-salt solutions