@misc{oai:repo.qst.go.jp:00079684,
 author = {Hirato, Misaki and Fujii, Kentaro and Shin-ichi, Wada and Baba, Yuji and Yokoya, Akinari and Hirato, Misaki and Fujii, Kentaro and Yokoya, Akinari},
 month = {Dec},
 note = {The aim of the present study is to clarify the electronic states of DNA related molecules incorporating a bromine atom. Since cells with DNA incorporating 5-bromouracil (BrU) as a thymine analogue have been known to be highly sensitive to ionizing irradiation, BrU is expected to be pharmacological agents as a sensitizer in radiation therapy. Previously, a radiation-track simulation study proposed a mechanism that hydrated electrons produced by water radiolysis could react with Br-DNA to form damage [1]. A recent EPR study reported that the bromine atom changes the yield of unpaired electrons in the uracil moiety [2]. In order to understand the physicochemical nature of Br-DNA, we investigated the binding energies of inner shell electrons of particular atoms in the DNA molecule using X-ray photoelectron spectroscopy (XPS) and X-ray Absorption Near Edge Structure (XANES) around the energies of C, N, O, P and Br K-absorption edges. Thin film samples of 5-bromo-2’-deoxyuridine-5’-monophosphate (BrdUMP) and thymidine-5’-monophosphate (TMP) were used for the spectroscopies. Obtained results indicate that the photoelectron binding energies, as well as the absorption edge energies, were similar for those sample molecules regardless of binding of a bromine atom. Contrary to the initial expectation, it is concluded that a bromine atom does not significantly contribute to the inner shell or unoccupied states in these molecules. Effect of bromine atom on the valence electronic states should be addressed in future studies.
[1] Watanabe and Nikjoo Int. J. Radiat. Biol. 78, 953-66 (2002).
[2] Oka et al. Appl. Phys. Lett. 113, 243701 (2018)., 第3回QST国際シンポジウム「Quantum Life Science」},
 title = {Study of electronic structure of Br-incorporated DNA related molecules},
 year = {2019}
}